Merge pull request #2 from tqhien/master

Changes in QGis 2.0 API

Thanks
set fill to none for polys with 'No Brush'
now also possible to write ALL features

user wants to write all features for given scale instead of only
the features that are into current mapcanvas
this changes makes this possible, but we have to change gui also
version 0.8 see metadata.txt for changes
QGIS 2.0 now uses SIP v2 so some QVariant types don't exist anymore
That's the case for QString.

Also added qgismaximumversion in metadata for QGIS2.0 plugin manager
compatibility