Update i18n strings.

Exclude pinned providers and tests from the bitmask.pro generator since
there is no strings to translate in there.
Replace triple dot character with 3 dots.

The string was unicode and the conversion was troublesome, was displayed
badly on transifex.
Handle removals on the updater repo
Fix typos on strings and remove unused button.

This was reported by the user 'strel' on transifex.
Set version to 0.7.0 and date to the rc1 date.
Better error message for PostLimitError.

Suggested by user 'kingu' on transifex.
Fold in changes

Update release date and version name.
Update requirements to use newer Soledad.
Update release date and version number.
Remove email instructions/reference. Closes #6140.

- cleanup some code,
- remove unused import,
- pep8 fixes
Add support for the internal LXDE polkit agent.

Closes #6043.