cmake: improve OOT projects find the installed GNU Radio.

1. Do not install FindGnuradio.cmake; everything is done through GnuradioConfig.cmake.

2. Fix a small bug with finding the PMT library if pkg-config is used.

3. Updated the documentation for how to use these tools in the OOT project.
cmake: adding library suffix variable for setting the cmake install directory.
qtgui: fixes to allow QTGUI to build on Gentoo.
grc: fixes issue of needing [] around the core affinity field in GRC.

Check for minoutbuf was buggy.
gr-analog : Fix initialization bugs in cc anf ff power squelch blocks.

Addresses Coverity issues 1043286 and 1043285.

Signed-off-by: Philip Balister <philip@balister.org>
gnuradio-runtime : Fix uninitialized variable.

Addresses Coverity 1043304. If either deserialize_untagged fails, goto the
error handler. Original code probably worked, since if one call failed, the
other would.

Signed-off-by: Philip Balister <philip@balister.org>
gr-fec : Fix uninitialized variable error.

Addresses Coverity issue 1043258. Code likely worked since d_count is only
used with the % operator. I think there is a potential rollover bug in the
code and the use of % is a performance issue. This code needs some more
janitor work.

Signed-off-by: Philip Balister <philip@balister.org>