as we want to release darktable 1.6 some time at the end of the year, it now is the time to announce the string freeze. Please don’t change any UI strings any more, so translators have a chance to catch up.
Translators: your updates should be committed to the master branch, there is no branch-off for a stable 1.6 version yet.
We should have the first release candidate packed up soon!
Having said this, the database should be stable (as it almost always is during development) and upgrading to master now with switching back to the release version later should not break things. As usual, make a backup before and be aware of the fact that you can't switch back to 1.4.2 with the database once opened with git master.