* configure.ac (NEED_NTBTLS_ABI, NEED_NTBTLS_VERSION): New.
(HTTP_USE_NTBTLS): New. Prefer over GNUTLS.
* m4/ntbtls.m4: New.
* m4/Makefile.am (EXTRA_DIST): Add new file.
* common/http.c: Add conditionals to eventually use NTBTLS.
--
This is only the configure stuff. If you have NTBTLS installed GNUTLS
will not be used but there won't be any https support either :-(.
This patch is used to have a real world test bench for the forthcoming
library.