Since multiframe changes can remove and create new frame items,
it's not safe to directly manipulate frame items in
QgsComposerItemCommand. Now, commands which apply to a frame always
fetch a reference to the correct frame item directly from the
parent multiframe. Also added unit tests for this crash.
- update methods of existing classes
- add comment to methods missing in the sip bindings
- split up collective sip files into single files and use
same directory structure in python/ as in src/
- add a lot of missing classes (some might not make sense because of
missing python methods in those classes)
- remove some non-existing methods from the header files
- add scripts/sipdiff
- replace some usages of std::vector and std::set with QVector/QSet
