Refactoring: move message quoting when replying into the Composer
Add some basic tests for quoting
SVN_SILENT made messages (after extraction)
Composer: do not rewrap text which is a quotation

In short, this prevents erroneous wrapping where the quoted lines which are
expected to be pre-wrapped would get wrapped again, but with a wrong quotation
level.
Ubuntu: Fix linking static plugins in CMakeLists.txt

REVIEW: 118124
SVN_SILENT made messages (after extraction)
Ubuntu: Fix ImapAccess::passwordWatcher non NOTIFYable property warning

REVIEW: 118146
Typo fixes, thank to Caspar
Merge branch 'quote-replying'

REVIEW: 118125
Make attempts to reconnect after a network error
After switching to offline mode due to a network error, the model tries to reconnect repeatedly, with increasing timeouts.
This is done until either trojita gets a working connecton, or reconnect attempts are aborted by choosing network:offline in the menu.

BUG: 327651
REVIEW: 118079