Add missing types to database API
Add more dict methods and easier insertion (database API)
Fix simple query and update (database API)
Fix update after querying (database API)
Minimal task's context file support
Fix SIGSEGV when re-opening the same file in the explorer

The problem was caused by not deleting the "pointer" from the modules dict, so then self.tree.CollapseAndReset(module) was accesing a stale wx tree item (already deleted)
Track open/closed state on task context files
Add delete shortcut and minor fix on update (database API)
Enhance simple rows query and fetching (database API)
Persist and restore task breakpoints
Normalize internal breakpoint line number handling

 * Editor (STC) is 0 based
 * Debugger (python) starts at 1 (so this is stored in the DB)
Add default database section to dist conf file
Minor improvement to database persistence
Track active total time per task context file (to calculate relevance)
Highlight relevant files in the repository browser

 * A slider was added to control the relevance threshold (0 to 100)
 * Filter out files in the repository that are bellow relevance (0 doesn't filter)
 * Grayed out files according their relevance (remarking in bold the ones > 33%)