While working on v1.0.5-maint (the branch in use on Fedora 19)
with the host at Fedora 20, I got a failure in virstoragetest.
I traced it to the fact that we were using qemu-img to create a
qcow2 file, but qemu-img changed from creating v2 files by
default in F19 to creating v3 files in F20.  Rather than leaving
it up to qemu-img, it is better to write the test to force
testing of BOTH file formats (better code coverage and all).

This patch alone does not fix all the failures in v1.0.5-maint;
for that, we must decide to either teach the older branch to
understand v3 files, or to reject them outright as unsupported.
But for upstream, making the test less dependent on changing
qemu-img defaults is always a good thing.

* tests/virstoragetest.c (testPrepImages): Simplify creation of
raw file; check if qemu supports compat and if so use it.
Signed-off-by: NEric Blake <eblake@redhat.com>
(cherry picked from commit 974e5914)

Conflicts:
	tests/virstoragetest.c - hardcode test to v2, since this branch doesn't handle v3 correctly

On Win32 symlink() is not available, so virstoragetest.c
must be conditionalized to avoid compile failures.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

virstoragetest was failing on RHEL 5, but with no good error message:

TEST: virstoragetest
                                        0   FAIL

It turns out that qemu-img was so old, that it lacked support for
-o backing_file.  It didn't help that the test was also using
qemu-img from PATH, even after first probing for kvm-img.

* tests/virstoragetest.c (testPrepImages): Consistently use
discovered binary.  Skip instead of fail if qemu-img fails during
setup.

On RHEL 5, I noticed this test failure message:

TEST: qemumonitorjsontest
libvirt not compiled with yajl, skippingSKIP: qemumonitorjsontest

* tests/virstoragetest.c (testPrepImages): Use simpler fputs.
* tests/qemumonitorjsontest.c (mymain): Ensure trailing newline.

Testing our backing chain handling will make it much easier to
ensure that we avoid issues in the future.  If only I had written
this test before I first caused several regressions...

* tests/virstoragetest.c: New test.
* tests/Makefile.am (test_programs): Build it.
* .gitignore: Ignore new files.