Added a rebuild-graph operation that fixes errors in the graph database.
fixed usage of file remotes in windows

harddrive letter was identified as protocol instead of "file:"
Remove GtEntityType in favor of FieldType
merge branch jdgarret/rebuild-graph
Add truncate() method to GraphDatabase and use it in RebuildGraphOpTest.java.

RebuildGraphOpTest.java was calling on File.delete() without checking for the return code
and with a non empty directory, so File.delete() was surely returning false, hence the graph
wasn't being deleted, hence the test succeeded cause the db didn't change at all.
Remove obsolete ObjectDatabase.getRaw(ObjectId):InputStream method
Merge branch 'fieldtype' of github.com:dwins/GeoGit into dwins-fieldtype
fix compile errors after merging dwins-fieldtype branch
Merge pull request #425 from volaya/remotes_win

fixed usage of file remotes in windows
Fixed an issue which caused rebuild-graph tests to fail.

GraphDatabase:put was incorrectly reporting that nodes
pointing to the root were being updated.
Merge branch 'rebuild-graph' of github.com:jdgarrett/GeoGit into jdgarrett-rebuild-graph