fix more graduate renderer crashes (followup d99d2fd97)
[TRANSUP] transifex translation updates

Signed-off-by: Werner Macho <werner.macho@gmail.com>
invert back toggle editing button in relation editor widget (fixes #11524,
followup b1a2bef1)
Less verbose debug output in layer tree model
update changelog for 2.6 release
Bump version to 2.7
support icons in map layer actions