Feature/gaia mission merge (#766)

* Add Adam Aslegård's module that renders Gaia mission stars
 * Add module for Gaia mission
 * Add CCfits and cfitsio submodules and the implemented fitsfilereader module from the OpenSpace-sun-earth-event branch
 * Add a TaskRunner to read from a fits file

modules/fitsfilereader/include/fitsfilereader.h

@@ -0,0 +1,116 @@
+/*****************************************************************************************
+ *                                                                                       *
+ * OpenSpace                                                                             *
+ *                                                                                       *
+ * Copyright (c) 2014-2018                                                               *
+ *                                                                                       *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of this  *
+ * software and associated documentation files (the "Software"), to deal in the Software *
+ * without restriction, including without limitation the rights to use, copy, modify,    *
+ * merge, publish, distribute, sublicense, and/or sell copies of the Software, and to    *
+ * permit persons to whom the Software is furnished to do so, subject to the following   *
+ * conditions:                                                                           *
+ *                                                                                       *
+ * The above copyright notice and this permission notice shall be included in all copies *
+ * or substantial portions of the Software.                                              *
+ *                                                                                       *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,   *
+ * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A         *
+ * PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT    *
+ * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF  *
+ * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE  *
+ * OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                                         *
+ ****************************************************************************************/
+
+#ifndef __OPENSPACE_MODULE_FITSFILEREADER___FITSFILEREADER___H__
+#define __OPENSPACE_MODULE_FITSFILEREADER___FITSFILEREADER___H__
+
+#include <string>
+#include <memory>
+#include <mutex>
+#include <unordered_map>
+#include <valarray>
+#include <vector>
+
+namespace CCfits {
+    class FITS;
+    class PHDU;
+    class ExtHDU;
+} // namespace CCfits
+
+namespace ghoul::opengl { class Texture; }
+
+namespace openspace {
+
+template<typename T>
+struct ImageData {
+    std::valarray<T> contents;
+    long int width;
+    long int height;
+};
+
+template<typename T>
+struct TableData {
+    std::unordered_map<std::string, std::vector<T>> contents;
+    int readRows;
+    long int optimalRowsize;
+    std::string name;
+};
+
+class FitsFileReader {
+public:
+    FitsFileReader(bool verboseMode);
+    ~FitsFileReader();
+
+    template<typename T>
+    std::shared_ptr<ImageData<T>> readImage(const std::string& path);
+
+    template<typename T>
+    std::shared_ptr<std::unordered_map<std::string, T>> readHeader(
+        std::vector<std::string>& keywords);
+    template<typename T>
+    std::shared_ptr<T> readHeaderValue(const std::string key);
+
+    /**
+     * Read specified table columns from fits file.
+     * If <code>readAll</code> is set to true the entire table will be read before the
+     * selected columns, which makes the function take a lot longer if it's a big file.
+     * If no HDU index is given the current Extension HDU will be read from.
+     */
+    template<typename T>
+    std::shared_ptr<TableData<T>> readTable(std::string& path,
+        const std::vector<std::string>& columnNames, int startRow = 1, int endRow = 10,
+        int hduIdx = 1, bool readAll = false);
+
+    /**
+     * Reads a single FITS file with pre-defined columns (defined for Viennas TGAS-file).
+     * Returns a vector with all read stars with <code>nValuesPerStar</code>.
+     * If additional columns are given by <code>filterColumnNames</code>, they will be
+     * read but it will slow doen the reading tremendously.
+     */
+    std::vector<float> readFitsFile(std::string filePath, int& nValuesPerStar,
+        int firstRow, int lastRow, std::vector<std::string> filterColumnNames,
+        int multiplier = 1);
+
+    /**
+     * Reads a single SPECK file and returns a vector with <code>nRenderValues</code>
+     * per star. Reads data in pre-defined order based on AMNH's star data files.
+     */
+    std::vector<float> readSpeckFile(std::string filePath, int& nRenderValues);
+
+private:
+    std::unique_ptr<CCfits::FITS> _infile;
+    bool _verboseMode;
+
+    bool isPrimaryHDU();
+    template<typename T>
+    const std::shared_ptr<ImageData<T>> readImageInternal(CCfits::PHDU& image);
+    template<typename T>
+    const std::shared_ptr<ImageData<T>> readImageInternal(CCfits::ExtHDU& image);
+
+    mutable std::mutex _mutex;
+};
+
+} // namespace openspace
+
+#endif // __OPENSPACE_MODULE_FITSFILEREADER___FITSFILEREADER___H__