Remove all mostly untranslated PO files

We only import PO files that are at least 75 % translated (8 % in
common), so we can delete now all other PO files. The patch only
removes the mostly untranslated files. Once a file becomes mostly
translated, the bot will import it again.

Change-Id: Iaea7a29267ee554d0d20b5cd050d453cea3798ba
Closes-Bug: #1317794
small edit to section_compute-configure-migrations

mount to plural - mounts it
changed , to .
added be before migrated
Split into separate sentences for clarity

Change-Id: Ic8f1ea2c0ae99a9a5ce007ce42db7ed48a37ea76
Merge "Remove all mostly untranslated PO files"
Merge "small edit to section_compute-configure-migrations"
Imported Translations from Transifex

Change-Id: Idfd7101c35ea4dbdc7d8325d52725e2d04209f3d