Started switching OpenSpace projects to nested namespaces

Various cleanups

src/documentation/documentationengine.cpp

@@ -45,8 +45,7 @@ namespace {
     const char* JsFilename = "${OPENSPACE_DATA}/web/documentation/script.js";
 } // namespace
 
-namespace openspace {
-namespace documentation {
+namespace openspace::documentation {
 
 DocumentationEngine* DocumentationEngine::_instance = nullptr;
 
@@ -322,5 +321,4 @@ std::vector<Documentation> DocumentationEngine::documentations() const {
     return _documentations;
 }
 
-} // namespace documentation
-} // namespace openspace
+} // namespace openspace::documentation

src/documentation/verifier.cpp

@@ -28,8 +28,7 @@
 
 #include <algorithm>
 
-namespace openspace {
-namespace documentation {
+namespace openspace::documentation {
 
 // The explicit template instantiations for many of the commonly used template values
 // This cuts down on the compilation time by only compiling these once
@@ -348,5 +347,4 @@ std::string OrVerifier::documentation() const {
 }
 
 
-} // namespace documentation
-} // namespace openspace
+} // namespace openspace::documentation