Added onBackPressed overrides in activity's

Added logoutButton check in facebookMainFragment
Added check for challengee in challengeCreate
Edited regex check in challengeCreate
Merge branch 'master' of https://github.com/madnessxd/almende

Conflicts:
	AlmendeMotivator/src/alm/motiv/AlmendeMotivator/ChallengeCreateActivity.java
	AlmendeMotivator/src/alm/motiv/AlmendeMotivator/ChallengeOverviewActivity.java