Avoid link errors with "configure --disable-shared".

Avoid link errors with "configure --disable-shared".

* src/Makefile.am: Create a convenience library, libvirt_test.la,
and don't restrict access to *its* symbols.
* tests/Makefile.am (LDADDS): Add ../src/libvirt_test.la, so that
"configure --disable-shared" no longer provokes link errors.
(LIBVIRT): Remove definition.
(LDADDS): Remove use.
($(LIBVIRT)): Remove rule.
(LDADDS): Use the new convenience library instead.
(CLEANFILES): Define.
* docs/examples/index.py (dump_Makefile): Append $(COVERAGE_LDFLAGS),
to the LDADDS definition, to avoid link error with the combination of
--enable-test-coverage and --disable-shared.
* docs/examples/Makefile.am: Regenerate.
* docs/examples/index.html: Likewise.
* qemud/Makefile.am (libvirtd_LDFLAGS): Append $(COVERAGE_LDFLAGS).
* src/libvirt_sym.version: Remove some SP-before-TAB.