logic: added Gradle project setup (issue #379)

* added implementation for Gradle project setup (icon is still missing)
* refactored project loading/saving and SourceGroupSettings
* removed long deprecated Cxx UseSourcePathsForHeaderSearch option

fortune cookie message = There is true and sincere friendship between you and your friends.

src/lib_java/project/SourceGroupJavaMaven.h

@@ -0,0 +1,29 @@
+#ifndef SOURCE_GROUP_JAVA_MAVEN_H
+#define SOURCE_GROUP_JAVA_MAVEN_H
+
+#include <memory>
+#include <vector>
+
+#include "settings/SourceGroupSettingsJavaMaven.h"
+#include "project/SourceGroupJava.h"
+
+class SourceGroupJavaMaven: public SourceGroupJava
+{
+public:
+	SourceGroupJavaMaven(std::shared_ptr<SourceGroupSettingsJavaMaven> settings);
+	virtual ~SourceGroupJavaMaven();
+	virtual SourceGroupType getType() const;
+	virtual bool prepareIndexing();
+
+protected:
+	virtual std::vector<FilePath> doGetClassPath();
+
+private:
+	virtual std::shared_ptr<SourceGroupSettingsJava> getSourceGroupSettingsJava();
+	virtual std::vector<FilePath> getAllSourcePaths() const;
+	bool prepareMavenData();
+
+	std::shared_ptr<SourceGroupSettingsJavaMaven> m_settings;
+};
+
+#endif // SOURCE_GROUP_JAVA_MAVEN_H