We were calling g_module_symbol() 2703 times, which is actually more
expensive than you'd think.
It also means the plugins are actually what we tell people they are:
A set of vfuncs that get run. The reality before that they were dlsym'd
functions that get called at pretty random times.
We only had to pile everything into the src/fuzzing/firmware directory
because honggfuzz could not cope with more than one input path.
This way each plugin is self contained and easy to copy.
Also, install the fuzzing builder objects as this fixes the installed
tests when srcdir does not exist.
Based on a patch by Jan Tojnar <jtojnar@gmail.com>, many thanks.
