Created the pop-up for groupSuggestion
Added layout of userRow for group suggestion dialog.
Finished the functionality implementation of the pop-up for group suggestion and added necessary API modification.
Fixed the moment when the group suggestion pop up is displayed.
Fix a risk of pop-up pile up
Fixed a couple Checkstyle violation in GroupsActivity
Fixed a bug with group suggestion dialog.

The bug was that the App's state was not consistent anymore if the user dismissed the dialog using the BACK key instead of the Cancel button. Booleans were not updated.
Restored the frequency of refresh of GroupsActivity to 2 minutes (was 10s for testing purposes).
Merge branch 'groupSuggestion' of https://github.com/lca4/unison-android into groupSuggestion
Updated JsonStructs to the ones found on the server.
forgot to add a file in previous commit solving a bug with the popup
Merge branch 'groupSuggestion' of https://github.com/lca4/unison-android into groupSuggestion
Almost finished implementing location management. WARNING code is buggy, we still need to replace Position by Pair<Double,Double> in order to serialize it
Fixed some Checkstyle violation and added the autoleave functionality to MainActivity. Not tested for now.
Removed uid from URL in requests for suggestions.
Added intervals for location fetching. Added the Set Password in menu when DJ (not the functionality behind).
Merge branch 'groupSuggestion' into master

Conflicts:
	res/menu/menu.xml
	src/ch/epfl/unison/api/UnisonAPI.java