Update Python parser with new keywords etc
Fix for Python 3.3’s new ImportError
Remove backwards compatibility with older Grail versions

* Use current “pickle” protocol 3
Update documentation with changes for newer Python version
Change bookmarks pickle format to version 5, incompatible with 4

Changes that make it incompatible are:

* Modules referenced by the pickle are moved under “grail” package
* Pickle protocol raised to version 3
* “mtime” field now recorded as a float() type