Adding some restrictions of time about checkins

Description:
EnteredCheckin should happen before LunchCheckin and after
LeavingCheckin
LunchCheckin should happen before LeavingCheckin and after
EnteredCheckin
LeavingCheckin should happen before LunchCheckin and before
EnteredCheckin
Some string names refactoring

Commit:Add

TaskNumber:#t6
Adding test for checkins restriction

Description: First test about checkin restriction

Commit:Add

TaskNumber:#t6
Merge branch 'testSharedPreference'

Conflicts:
	.gitignore