We were using "llvm-config --bindir" to set the path for clang. But
on some systems clang is not in that directory. Changed the configure
script to search for clang in the bindir first, if not found, search
the normal locations.
refs #130
Added a configure check for clang and llvm-config. If llvm-config exists
then we check for the libraries in the libdir returned by llvm-config.
All of these must be present for configure to pass.
refs #130
So I found that I didn't write many of the autoconf rules correctly including
the one searching for motif. I also messed up the checks for bison, flex, and
perl. I added new rules to search for Xwindows headers and libraries. The
motif rule is only executed if we find fermi-ware where it is used.
refs #119
Added AX_PTHREAD to the configure.ac script. This change forces us to
have install-sh, config.sub and some other autoconf files. Created
an autoconf directory to hold these files. Changed the makefiles to
use the PTHREAD variables coming out of configure.
refs #69
