This enum was forcing an include of qgscoordinatetransform.h within the
widely used qgsabstractgeometry.h header, causing an absolute explosion
of includes of a bunch of very heavy header classes all across QGIS. By
removing the forced include we can avoid a ton of unwanted includes
and make wider use of forward declarations...
- Add enums to qgis.h instead of qgscoreenums, so that they belong to
a Qgis namespace
- Split up the various symbol headers into multiple files so that we
can fine-tune their inclusion and forward declare more readily, speeding
up recompilation
- Move QgsSymbol enums to qgis
