Upgraded to the latest conformance suite
Change default short URL length.
Fix warnings.

Tests will fail until conformance tests would be updated.
Update submodule URL for twitter-text-conformance
Refactoring around initialization of endMentionsRegexp
Use dispatch_once for thread safety
Include json-conformance tests to the repo
Update HTTPShortURLLength & HTTPSShortURLLength

Update HTTPShortURLLength & HTTPSShortURLLength ready for upcoming t.co changes.
Merge pull request #4 from ay8s/master

Update HTTPShortURLLength & HTTPSShortURLLength ready for upcoming t.co changes.
Allow '@' in URLs
Update project
Upgraded to the latest conformance suite
Update comformance tests
Merge remote-tracking branch 'upstream/master'

* upstream/master:
  Update comformance tests
  Upgraded to the latest conformance suite
  Update project
  Allow '@' in URLs
  Update HTTPShortURLLength & HTTPSShortURLLength
  Include json-conformance tests to the repo
  Use dispatch_once for thread safety
  Refactoring around initialization of endMentionsRegexp
  Update submodule URL for twitter-text-conformance
  Change default short URL length. Fix warnings.
  Upgraded to the latest conformance suite

Conflicts:
	.gitmodules
	test/twitter-text-conformance