* open custom trail dialg via button in top of trail controls
* search from symbol to symbol or all referenced/referencing of symbol
* define search depth with slider
* define horizontal/vertical layout
* define node and edge types
* renamed depth graph to trail in graph ui
* added custom trail UI tests
fortune cookie message = A happy surprise is waiting for you.
* 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
* fixed case where "to-index" state of a file has changed and thus the file needs to be re-indexed
* clear and re-index files that depend on changed non-indexed files
* clear and re-index files referenced by unchanged but cleared (due to referencing a changed file) files
* fixed: updated files with changed timestamp that do not have content in the db will now count as changed
* refined refresh info generator tests
* updated checklists for manual project setup tests