instead of individually setting map canvas, expression context, etc
Will make it more easy in future to add additional parameters
to the widget context
This means that symbol selectors can be aware of the correct variable
scope and values for both populating expression builder widgets and
for symbol previews.
- 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
