add basic mysql support
make mysql dialect only contain the differences to postgres, for ease of maintenance
missing break in setDialect
add mysql order by column format. mysql doesn't allow brackets around the order items.
correctly visit direction text node on postgres and correct test to only have one space before direction
quote aliases, quote all table names and add more support for mysql
alter tests to take quoted aliases into account, add support for testing more than one dialect, add all test cases for mysql.
The test/postgres directory should probably be renamed to test/dialects
remove duplicate requiring of dialects
let the tests say which dialect they are for
globally replace quote character in quoted identifiers, and add a test case for this
Merge pull request #42 from HughePaul/master

"experimental" mysql support