Added Event tracking for user sign in attempts
Added event tracking for chat initialization
Merge branch 'development' of https://github.com/barterli/barterli_android into analytics

Conflicts:
	barter.li/src/li/barter/fragments/ProfileFragment.java
Added analytics code for checking usage of adding manually vs barcode scan
Added analytics for no of clicks on books from profile page, added is logged in parameter to all events
Moved Crashlytics intialization code to barter.li application
Added analytics for measuring navigation drawer clicks
Moved all screen names to a single file
Merge branch 'development' into analytics

Conflicts:
	barter.li/assets/crashlytics-build.properties
	barter.li/res/values/com_crashlytics_export_strings.xml