basic recovery
connection recovery working, warning: pubspec modified for dev purposes
clientVersion argument in DataProvider methods made optional, minor fixes
removed test code
removed _requestQueue, modified _sentItems inner structure, simplified the resync protocol, all changes are sent to server which is responsible for skipping already applyied changes
connection recovery finished, test added
fixed test
concurent-modification bug fixed
Merge branch 'master' into connection_recovery, tests failing, random_subs test passing

Conflicts:
	lib/src/mongo_provider.dart
debugging
bugfixing, polishing
Merge pull request #50 from cleandart/connection_recovery

Connection recovery