update Simplified Chinese (zh_CN) translation
Added Latvian translation
Updated Latvian translation
Updated email address
Renamed async methods from flicksoup to omit the '_async' suffix.

No need to do this if they are always asynchronous. Updated callers.
gthread_init() is deprecated in glib 2.32
g_type_init() is deprecated in glib 2.36
Added Indonesian translation
Remove unnecesary includes
Added galician translations for doc
Integrate FrogrPictureUploader into FrogrController.

This helps reduce the global code base while, at the same time, helps
simplify the whole process by avoiding passing too many callbacks
around and keeping all the stuff related to FspSession in one place.
Renamed FrogrPictureLoader to FrogrFileLoader.

One day frogr will also load / upload other kind of media (e.g. videos).
Replace callbacks in FrogrFileLoader with signals, to be used from the controller.
Remove unused signals from FrogrController
Don't give up on upload too early and retry some times instead.

This might be useful for flaky connections or for temporary
problems in the server side of the communication.
Removed textual feedback on minor operations (setting license, adding to sets...)

This is a previous step to make all those operations work in paralell.
Make after-upload operations work in paralell.

These currently are setting the license, setting the location, adding
a picture to sets and adding a picture to groups.
Fixed memory and reference handling issues, related to how objects and lists of objects
were being passing around among the main window, dialogs and the controller.
Removed unused flags in FrogrController
Refactor finishing the upload of one picture and fix a leak