Add cmake finds for autoconf/automake and flex/bison #23
Description
Needed by charm (and probably some other TPLs) and doxygen, respectively. CC @rfbird
Also
- Charm assumes perl has Thread::Queue enabled/installed
- Also add search for: m4, libtool
- Do not generate targets for which TPLs's headers are not available, e.g., Control. Done by Make non-executable targets conditional on TPLs found quinoa#290.