fix handling of opacity when rendering svg with cairo - closes #1943
optimize svg rendering by moving bbox calc only needed by gradient rendering into gradient code
add testcase for #1944
fix svg parser to ignore empty groups - closes #1944
Avoid truncating 64 bit return values on 32 bit platforms
Drop bogus assertion

Comparing to sys.maxint makes little sense as all it is doing is
testing the size of python's integers. The following assertion tests
that we are getting the correct return value anyway.
Numeric return results are now long rather than int
Stop the osm input plugin truncating ID values on 32 bit platforms
Merge pull request #1946 from tomhughes/osm

Stop the osm input plugin truncating ID values on 32 bit platforms
Merge pull request #1945 from tomhughes/python

Fix numeric truncation issues in python bindings