Added more server side stuff

SQL is now parsed on the server side.
Also, I now protect against multiple metadata links, i.e. if a SQL
statement has multiple instances of the same identifier or keyword, only
one SQLStatementMetatdata row is created.
deal with multiple flushers flushing same sql buffer
Merge pull request #48 from dannybutler/master

Added more server side stuff
Merge branch 'master' of https://github.com/artsalliancemedia/cherry_pyformance