Use ${CMAKE} instead of cmake.
Merge pull request #374 from hashdist/johannr/cmake-fixes

Use ${CMAKE} instead of cmake.
Add missing variables MPIFOO for OpenMPI.
Merge pull request #375 from hashdist/johannr/openmpi-add-missing-variables

Add missing variables MPIFOO for OpenMPI.
Fix flex for building on Darwin.
Merge pull request #376 from hashdist/johannr/flex-no-undefined

Fix flex for building on Darwin.
Refactor scotch and add missing dependencies on flex and bison.
Initial add of cloog needed for gcc
Inital add of isl needed for gcc
Initial add of mpc needed for gcc
Initial add of gcc compiler suite
cloog: expose pkgconfig and bin paths

cloog uses pkgconfig and has a binary which might be used when it's
called as a build depenendency.
gcc: parameterise the configuration step

Building gcc on OSX 10.9 and Ubuntu Precise (64bit) appears to be have
differently. So breaking out the configurations for each platform.
gcc: Parameterise gcc package

Use a python script to try and deal with Linux/OSX differences and also
problems with LD_LIBRARY_PATH.
gcc: Comment reasoning for the flags used
gcc: Don't use LD_LIBRARY_PATH during build

Tell configure about boot and stage1 ldflags to avoid the usage of
LD_LIBRARY_PATH.
gcc: Tell compiled gcc where to look for headers

This option tries to build a gcc install that is more insulated from
the system.
gcc: Set non-relocatable
gcc: Ensure libraries get installed into lib

By default gcc installs 64bit libraries into lib64, we change it here
to install into lib instead.
gcc: Record some information after a build

Record lookup paths that gcc is built with so user can look up its
behaviour if needed.