Update python docstrings

Merging master branch on release and tagging as 2.2.0

Fix cmake broken support option

Need to check for Empty attribute

This commit fixes test: TestvtkGDCMMetaImageWriter

merge trunk into branch, with remaining bits (again)

obfuscate niels emails (backport from branches/gdcm-2-0)

revert

BUG: Backport rev 6186. svn merge --accept=postpone -r 6185:6186 http…

…s://gdcm.svn.sourceforge.net/svnroot/gdcm/trunk

backport remaining stuff from trunk