* implemented handling of aggregations in bookmarks
* split index Storage and bookmark storage
* each sqlite database has its own version now
* added bookmark tests
* fixed creating bookmark tables when project can be loaded but bookmark db does not exist
* fixed font size for bookmarkview tooltips
* using bookmark cache now
* using default category name when none specified by the user
* raising bookmark windows when they should be shown
* clearing a bookmark or category in the editor will now update the star icon accordingly
* non-persistent bookmarks use ids of nodes and edges now (instead of names)
* git ignore .srctrlbm files