Updated AUTHORS, COPYING, DISCLAIMER, and INSTALL files. Added
standardized headers to all source file to clearly indicate the
copyright, license, and to give credit where credit is due.
SPL_AC_2ARGS_SET_FS_PWD macro updated to explicitly include
linux/fs_struct.h which was dropped from linux/sched.h.
min_wmark_pages, low_wmark_pages, high_wmark_pages macros
introduced in newer kernels. For older kernels mm_compat.h
was introduced to define them as needed as direct mappings
to per zone min_pages, low_pages, max_pages.
