Show folder icon a offline when account is offline

Fixes #1959
Merge pull request #2064 from owncloud/fix-1959

Show folder icon a offline when account is offline
Remove owncloud_logo_blue.png from mirall.qrc resource

It not used in mirall itself.
SyncEngine & UI: Progress notifications for update phase

For each directory (local and remote, we have UI update throtting code)
a signal is emitted.
It is used by the settings dialog and the tray menu.
CSync: Add a 30 second connect (not read) timeout
SyncEngine & UI: Make the function part of UpdateJob

That way we can easily emit UploadJob's signals
SyncEngine & UI: Move QElapsedTimer to object

Using a function static is too dangerous when multiple threads are involved.
Nautilus Overlays: Use port 34001 by default.
Nautilus Overlays: Fix: do not change an dictionary which is iterated.

Also, item.invalidate_extension_info() is sufficient, no need to call
update_file_info afterwards.
Tests: Fixed the CSync statedb test defined in the mirall module.
subject verb agreement
Use QStandardPaths for linux if building with qt>=5
[tx-robot] updated from transifex
[tx-robot] updated from transifex
Merge pull request #2067 from owncloud/grammar

subject verb agreement - very good, thanks.
[tx-robot] updated from transifex
space
[tx-robot] updated from transifex
Settings: Display the commit SHA both in branded and unbranded.

Also, do not put the developer names into the translation string.
Update phase progress: Check if callback is defined.