logic: paths in ProjectSettings relative to file not working directory

This change checks all paths in the ProjectSettings file for relativity and makes them relative to the location of the
ProjectSettings file if necessary. The paths are also correctly saved relative to the file.

src/lib/settings/ApplicationSettings.cpp

@@ -21,6 +21,22 @@ std::string ApplicationSettings::getStartupProjectFilePath() const
 	return getValue<std::string>("StartupProject", "");
 }
 
+std::vector<FilePath> ApplicationSettings::getHeaderSearchPaths() const
+{
+	return getPathValues("source/HeaderSearchPaths/HeaderSearchPath");
+}
+
+std::vector<FilePath> ApplicationSettings::getFrameworkSearchPaths() const
+{
+	return getPathValues("source/FrameworkSearchPaths/FrameworkSearchPath");
+}
+
+std::vector<std::string> ApplicationSettings::getCompilerFlags() const
+{
+	std::vector<std::string> defaultValues;
+	return getValues("source/CompilerFlags/CompilerFlag", defaultValues);
+}
+
 std::string ApplicationSettings::getFontName() const
 {
 	return getValue<std::string>("application/font_name", "Source Code Pro");