Add the files in resources/ to soup-test.gresource, and add
soup_test_load_resource() to get the contents of one of them, and then
use this in places that were previously reading them by hand.

Except forms-test, which needs to pass a filename to curl, so have it
use index.txt instead of one of the resource files.

Now none of the tests access the resources/ directory at runtime.

Also add soup_test_get_index() to read index.txt rather than
reimplementing it in multiple test programs.

Some programs need to be split up into more tests, and the debug
output is mostly not updated for the new format.

Fix up a couple of errors picked up by -Werror=format-nonliteral on
clang.

https://bugzilla.gnome.org/show_bug.cgi?id=720082

The function gets a new parametter used to enable request cancellation for
both sync and async sessions. The cancellation could be performed by either
using the GCancellable or by directly cancelling the SoupMessage.

Also the GMainContext used to simulate sync operations with async ones will
now try to execute all its pending events before quiting the main loop.

https://bugzilla.gnome.org/show_bug.cgi?id=692310

SoupMessage isn't being deprecated, and mirroring its API onto
SoupRequestHTTP is just going to result in always having to add every
new API twice. Also, it turns out to be less useful than originally
expected anyway, since you end up having to cast between SoupRequest
and SoupRequestHTTP frequently anyway.

This reverts commit d7117329400e47d2187ed033099d921d555f8d71 and most of
commit 53c270d0e2868fa5ad48ce864f10a9486b11a071.

Add SoupSession helpers to return SoupRequestHTTP directly and allow
overriding the request method.

Add soup_session_request() and soup_session_request_uri(),
implementing basically the same behavior as soup_requester_request()
and soup_requester_request_uri() (but without requiring a separate
SoupSessionFeature), and remove the unstable-api ifdefs from
soup-request*.h.

SoupRequester still exists, but it is still guarded by the
unstable-api ifdefs, and is just a dummy wrapper around the
functionality that is now in SoupSession.