timeout while running testclidriver

there are ~200 tests right now, and it sometimes takes more than 30 min (which is the current timeout).

The potential fixes are:
1. Increase the timeout to 45 min.
2. Reduce the time for some big tests (like groupby_bigdata.q).

We should do both of them. In order to test groupby_bigdata.q, we need to run the mapper/reducer with less memory. Since it is not
a supported feature for hadoop right now in local mode, a new variable can be added for the same. The new configurable parameter will
only work in local mode