- bump AUTOCONF_VERSION to 2.71: is what upstream uses to generate the
tarball anyway.
- add new LDEP on libqrencode.
- disable gdk-pixbuf dependency: is used only to scale avatars before
uploading them and we seem to avoid big dependencies for profanity.
plus regen the patches and fix a typo in the configure: the generated
variable name is `enable_gdk_pixbuf' and not `enable_pixbuf'; otherwise
it always links to gdk-pixbuf even if disabled.
2a373dbe88