Fujitsu Sparc64 acceleration and general fixes for non-x86 builds

Fixes configurations not to assume x86 and avoid warnings, in
particular if a non-x86 acceleration is used.
The cpu detection code has been extended to parse /proc/cpuinfo on
Linux in cases where the x86 CPUID instruction (or the inline
assembly to execute it) is not available.
Finally, there are new group kernels accelerated for use on the
K computer, which uses the Sparc64 HPC-ACE instruction set. These
kernels are roughly ~35% faster than the compiled C version, which
means Gromacs-4.6 is now ~70% faster on K than Gromacs-4.5.

Change-Id: I92559f0ac6159b504f100447a41a03e4b33fec19