Add two new ErrorCodes for the data/metadata versions in fDB for being
out of synch with the fSQL data/metadata versions. 

in Main.java, make sure the error management only prints the message,
not a stack trace too.
Remove the "not used" comments.
Fix capitalization on error messages

Make metadataversion...exceptions subclasses of a common class to make
the check in Main cleaner.
merge tjoneslo: Incompatible meta data version error message

Merge pull request #1472 from tjoneslo/sql-layer/incompatible-meta-data-version-error-message
https://github.com/FoundationDB/sql-layer/pull/1472