[#ANDROID-155] Message Center can't scroll

Fixed Message Center scrolling on Android 2.3.x. Fix is to stop wrapping the Message Center ListView in a ScrollView.
Check in IDEA project file.
Update CHANGELOG, bump version.
Add ability to ad and remove individual pieces of device data.
Merge branch 'custom_data' into next

Conflicts:
	CHANGELOG.md
Merge branch 'custom_data' into next

Conflicts:
	CHANGELOG.md
Ignore bin/
Rename static device data field. Use new setCustomDeviceData() in apptentive-dev. Modify survey selection code to remove duplicate and empty string tags. Add method getUnreadMessageCount().
Merge branch 'master' into next

Conflicts:
	apptentive-android-sdk/src/com/apptentive/android/sdk/module/survey/SurveyManager.java
[#ANDROID-148] Use email_required setting from server configuration