configure & compiler warning cleanups
- configure: Use
LT_INIT
from libtool 2 instead of deprecatedAC_PROG_LIBTOOL
- Add X.Org's standard C warning flags to
AM_CFLAGS
- Quiet
warning: redundant redeclaration of ‘timingsafe_memcmp’
- Fix
warning: variable ‘pCg3’ set but not used [-Wunused-but-set-variable]