allow for expressions in symbol rotation and scale
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
changed std::auto_ptr for QScopedPointer
fixed bug in rotation & removed xml encode/decode
fixed toSld() & replaced "" by QString
fix bug in max value on joined fields
#87525R: refactoring and minor changes
#8725R: fix collapsed polygons by ST_simplify in postgis
#8725R: fix invalid LineStrings
fix build with GDAL <=1.9
[TRANSUP] pl: Globe, expr.editor
Merge pull request #1099 from ahuarte47/Issue_8725R-ST_simplify

Fix bug #8725R: fix collapsed geometries by ST_simplify function of postgis
Merge pull request #1101 from Cracert/i18n

[TRANSUP] pl: Globe, expr.editor
Merge pull request #1075 from Oslandia/expressions_in_symbol_rotation_and_scale_for_pr

[FEATURE] allow for expressions in symbol rotation and scale
Merge pull request #1083 from Oslandia/fix_max_on_joined_fields

fix bug in max value on joined fields
cleanup 3568fe7
fix empty expression when reading from OGC filter
Merge pull request #1105 from mwa/fix_expression_from_ogc_filter

Fix empty expression when reading from OGC filter