Instead of drop msgctxt, treat same as gettext-tools>=0.15.

tested with editors/medit and graphics/gimp and context specified translate
messages are appeared.
Update mikutter to mikutter.0.2.1.1142.

* fixes crash when recieve unknown entity format.
* openimg: update support of yfrog and instagram.
* extract: backport from 0.2.2, fixes crash.
* directmessage: fix to be fired when DM to myself.
Updated net/mikutter to 0.2.1.1142