By setting the CA file we make it a certificate error if the certificate
is self-signed.

Fixes: https://bugzilla.gnome.org/show_bug.cgi?id=663783

It will autodetect and also allow the setting of the CA file by a configure
option.

This code was stolen from glib-networking's configure.ac

Fixes: https://bugzilla.gnome.org/show_bug.cgi?id=663783

libtool needs -no-undefined to generate DLLs on windows. As that flag
can't hurt (on the contrary) for other platforms, just add it to the
LDFLAGS.

On Windows, I don't want to go through installing gtk-doc just to get some
DLLs compiled.

ACLOCAL_FLAGS allow you to define extra directories to look for m4 macros.
autoreconf parses Makefile.am to add ACLOCAL_AMFLAGS when invoking aclocal.

Adding ${ACLOCAL_FLAGS} to ACLOCAL_AMFLAGS make autoreconf grab flags from
the environment.

librest already had something to deal with it in autogen.sh, however having
it in autogen.sh does not help when regenerating the configure script
automatically (as automake now has rules to rebuild configure whenever
configure.ac changes, ie by-passing autogen.sh)

gcc complains about %lli here. Glib happens to define convinience macros
around gint64, let's use them.

Fixes: https://bugs.meego.com/show_bug.cgi?id=15086

This is neccessary for Vimeo because of a bug where we get a 500 error if we
pass along the cookie it provides.

Fixes: https://bugs.meego.com/show_bug.cgi?id=15015

Fixes: BMC#14749