* Added new Source Group type SourceGroupCustomCommand to UI and ProjectSettings
* The Source Group executes a specified command on every source file
* The variables $SOURCE_PATH, $PROJECT_PATH, $DB_PATH, $STORAGE_VERSION can be passed
* The commands are executed after all other source groups finished indexing
* The command is executed with working directory set to project directory
* Errors during command execution are shown as status update and in the Status View
* SourceGroupCustomCommand cannot be partially cleared, when one file needs clearing the project must be fully re-indexed
* implemented task for sending IndexerCommands to shared memory on demand
* SourceGroups now return IndexerCommandProviders instead of just a list of indexer commands. This way information can be stored in a compressed format
* merged IndexerCommandCxxEmpty and IndexerCommandCxxCdb
* moved sorting of indexer commands by file size from IndexerCommandList to TaskFillIndexerCommandQueue
* removed obsolete IndexerCommandList class
* wait for IndexerCommandQueue to be filled before starting the indexers
* restart finished indexer processes while indexerCommandQueue is still running
* restart indexer threads as long as there are indexer commands to process
* removed Blackboard::getMutex() and added an atomic update() method
* also changed xml elements in sourcegroup settings that specify the used language standard, so that one sourcegroup can maintain multiple language standards
* added migration and migrated sample projects
Eberhard Graether