Fixes several crashes and problems with backwards compatibility.
Before expressions were allowed, field names were loaded and saved
unquoted, e.g. x.y - with introduction of expressions it was
necessary to use properly quoted "x.y" name so that expression
is correctly parsed. With these changes both options are possible
and when possible, the unquoted field name is used for compatibility
the single, graduated and categorised symbol renderers have been
refactored to avoid use of raw pointers (auto_ptr are used instead, they
are deprecated in c++11 but the change for unique_ptr is an easy one and
they clearly state the design intend: exclusive ownership)
2 general use function to quote and unquote strings for/from xml have
been added to qgis.h
- 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
