Update APIChanges.md

Format with git markup.
Bump to 1.2.2. Update CHANGELOG.
Merge branch 'v1.2.2'
[#SUPPORT-42] Fix NPE in survey code. Send event when this potentially happens, because it shouldn't.
Create a new internal error reporting system. Catch exceptions that would otherwise crash the host app, and log them to the error reporting system instead. Log a possible crash due to survey list returning null from parsing code. Remove unused placeholder methods from Apptentive. Remove some dead code in FileMessageView.
Return boolean from Apptentive.showRatingFlowIfConditionsAreMet(). Return true if rating flow was shown. Update docs.