GridFire can now support unity builds. This is useful for python
bindings. The main limitation is that openssl (a dependency of
libplugin) does not support unity builds. Therefore when building in a
unity build libplugin must be disabled. This is done with the
-Dunity-safe=ture flag at setup time
GridFire failed to compile on gcc and gnu stdlibc++ this has been
resolved. Further, the boost dependency has been removed since we no
longer use boost at all. This should dramatically simplify installation.
Finally we have added some build system checks to ensure that the
correct version of a C++ and fortran compiler are present on the system
