MXS-1070
Now both qc_mysqlembedded and qc_sqlite return the same stuff
for the same statement, and both include also operators in
addition to pure functions. Whether that is the right approach,
is still subject to debate.
However, if we want to make it possible to disable e.g. the
use of concat as in "select concat(a) from t", where a is a string,
to prevent the bypassing of the masking filter, then conceptually
it should be possible to prevent "select a+0 from t", where a is an
int, as well.