improved postgis import with append option
doc improvements
started raster sld support
refactored uri dragging functionality
minor code improvements
Merge pull request #49 from vdeparday/master

Fix issue #48
remove unused code (for unused execution in separate thread)
fixed #50
added support for singleband gray scale as SLD
improved error messaging
Adding pyc file to .gitignore
First basic implementation of "Publish to GeoNode"
Merge remote-tracking branch 'upstream/master'
Delete some pyc files that were added to the repo before .gitignore was modified
Specify a layer owner to GeoNode in case we would want it to be different than logged user