static ALLOCATOR gets final
verified that DATABASE_URL now works as expected (even with JDBC props)

e.g. `rake db:version DATABASE_URL="mysql://localhost/rails32?prepared_statements=true&cachePrepStmts=true&cacheResultSetMetadata=true&profileSQL=true"`
[postgres] hstore values should be returned as Hash instances (fixes #454)
rebuild jar due changes
helper gems should contain all files from lib/* (thanks to @nertzy fix #463)

also reviewed limits impossed on driver versions - esp. for next postgres JDBC we will very likely be fine using 9.3