LU-4993 libcfs: convert nodemask_t to linux bitmask

Starting in 3.14 kernels nodemask_t was changed from a
a unsigned long to a linux bitmap so more than 32 cores
could be supported. Using set_bit in cfs_cpt_table_alloc
no longer compiles so this patch backports bits of the
node management function that use a linux bitmap back
end. Cleaned up libcfs bitmap.h to use the libcfs layers
memory allocation function. This was pulling in lustre
related code that was not defined.

Change-Id: I7d08425bc09af2c3c04f7e5ed7d50e7c27d165df
Signed-off-by: James Simmons <uja.ornl@gmail.com>
Reviewed-on: http://review.whamcloud.com/10332
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Liang Zhen <liang.zhen@intel.com>
Reviewed-by: Bob Glossman <bob.glossman@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>