Deprecates recordOnce. Adds RecordCondition to record methods. Archive and unarchive methods for InstallEvents added to ArchiverImpl.
Updates tests for saved identity events.
Updates tests for saved identity events.
Adds tests for saved install events. Updates names of saved id events tests for clarity.
Updated JavaDocs
Updates User-Agent.
The 2.1.0 jar.
Merge pull request #12 from kissmetrics/record-per-id

Adds an optional RecordCondition parameter to the ```record()``` method. RecordConditions include ```RECORD_ALWAYS``` (default), ```RECORD_ONCE_PER_INSTALL``` and ```RECORD_ONCE_PER_IDENTITY```. Deprecates ```recordOnce()```, which was the equivalent to using ```RECORD_ONCE_PER_IDENTITY```.