Provide a simple interface for other tests to lookup the testDebug variable.
Also remove a redundant error message in interface tests.

If anyone feels inclined to change this env variable to match the existing
LIBVIRT_* format, it should now be easier to do so.

* src/testutils.[ch]: make testDebug externally available

* src/testutilsqemu.c: if VIR_TEST_DEBUG is set, dump the qemu
  driver capabilities to stderr

* po/id.po: Likewise.
* qemud/remote_generate_stubs.pl: Likewise.
* src/virsh.c: Likewise.
* tests/testutils.c: Likewise.
* tests/testutils.h: Likewise.
* RENAMES: Likewise.

Done with these commands:
git grep -l Local.variab|xargs \
  perl -0x3b -pi -e 's,\n+/\*\n \* vim:(.|\n)*,\n,'

git grep -l Local.variab|xargs \
  perl -0x3b -pi -e 's,\n+/\*\n \* Local variables:\n(.|\n)*,\n,'

* Makefile.cfg (local-checks-to-skip): Remove sc_trailing_blank.
* .x-sc_trailing_blank: New file, to exempt the few binary files.