configure & compiler warnings cleanup
- configure: Use
LT_INIT
from libtool 2 instead of deprecatedAC_PROG_LIBTOOL
- Add X.Org's standard C warning flags to
AM_CFLAGS
- Fix
warning: variable ‘pCg14’ set but not used [-Wunused-but-set-variable]
- Quiet
warning: redundant redeclaration of ‘timingsafe_memcmp’ [-Wredundant-decls]