ASCII.
REPLACE.
{VAR,STDDEV}_{POP,SAMP}
Make ASCII be like MySQL's ASCII and UNICODE be like Postgres's ASCII (or SQL Server's UNICODE).
merge MMcM: Add some more functions

Merge pull request #1031 from MMcM/sql-layer/few-more-funs
https://github.com/FoundationDB/sql-layer/pull/1031