Code cleanup branch (#618)

* Make height map fallback layer work again
  * Add documentation to joystick button bindings
  * Removed grouped property headers
  * Add new version number constant generated by CMake
  * Make Joystick deadzone work properly
  * Change the startup date on Earth to today
  * Fix key modifier handling
  * Add debugging indices for TreeNodeDebugging
  * Fix script schedule for OsirisRex
  * Do not open Mission schedule automatically
  * Upload default projection texture automatically

  * General code cleanup
  * Fix check_style_guide warnings
  * Remove .clang-format
  * MacOS compile fixes
  * Clang analyzer fixes

modules/base/rendering/renderableplaneimageonline.cpp

@@ -27,15 +27,14 @@
 #include <openspace/documentation/documentation.h>
 #include <openspace/documentation/verifier.h>
 #include <openspace/engine/openspaceengine.h>
-
 #include <ghoul/filesystem/filesystem.h>
 #include <ghoul/io/texture/texturereader.h>
+#include <ghoul/logging/logmanager.h>
 #include <ghoul/opengl/texture.h>
 #include <ghoul/opengl/textureunit.h>
 
-
 namespace {
-    static const openspace::properties::Property::PropertyInfo TextureInfo = {
+    const openspace::properties::Property::PropertyInfo TextureInfo = {
         "URL",
         "Image URL",
         "Sets the URL of the texture that is displayed on this screen space plane. If "
@@ -66,8 +65,6 @@ RenderablePlaneImageOnline::RenderablePlaneImageOnline(
                                                       const ghoul::Dictionary& dictionary)
     : RenderablePlane(dictionary)
     , _texturePath(TextureInfo)
-    , _texture(nullptr)
-    , _textureIsDirty(false)
 {
     documentation::testSpecificationAndThrow(
         Documentation(),
@@ -149,7 +146,7 @@ void RenderablePlaneImageOnline::update(const UpdateData&) {
 }
 
 std::future<DownloadManager::MemoryFile>
-RenderablePlaneImageOnline::downloadImageToMemory(std::string url)
+RenderablePlaneImageOnline::downloadImageToMemory(const std::string& url)
 {
     return OsEng.downloadManager().fetchFile(
         url,