Quiet the Poller

Attached patch enforces the quiet (-q) option for the poller.

Rationale:
With the help of Xdebug and Webgrind, I found that the poller was spending a ton of time colorizing strings for the CLI. The first problem was that the poller-wrapper was not running the poller in quiet mode and was simply redirecting all output to /dev/null. The second problem was the the poller was ignoring the quiet option.

I define a global OBS_QUIET similar to OBS_DEBUG and simply short-circuit the print_* functions.