Another automake warning
Remove an unused variable
Convert pixbuf-randomly-modified test

Make this test use g_test_run, so it is compatible
with using TAP.
Convert pixbuf-threads test

Make this test use g_test_run, so it is compatible with using TAP.
tests: Use TAP

Instead of using gtester, switch to using the TAP support
and the automake test harness.
Updated POTFILES.in
Make configure check for awk

awk is needed for the automake tap driver.
Include config.h everywhere, first

Some of the loaders were not doing this.
Don't include config.h in any headers

config.h has no inclusion guards, so including it in headers
is bound to cause redefinition warnings from cpp.
Quell another automake warning
Allow single-character keys for tEXt chunks

The keys for tEXt chunks are documented as 1-79 character
ASCII strings. Testing this shows that we reject single-
character keys as too short. Fix that.
Add tests for saving
Enable coverage testing

Use --enable-coverage and make coverage to get it.
Remove Makefile.decl

We are now using glib-tap.mk for the tests, and all we gain
from Makefile.decl is a predefined EXTRA_DIST, which doesn't
seem worth it.
One forgotten instance of Makefile.decl
Two more instances of Makefile.decl
Declare the removal of Makefile.decl complete