build: expand rule to cover testsuite

build: expand rule to cover testsuite

The bulk of this patch was done with:

sed -i 's/\(\bfree *(/VIR_FREE(/g' tests/*.c

followed by fixing the few compile errors that resulted.

* cfg.mk (exclude_file_name_regexp--sc_prohibit_raw_allocation):
Remove tests from exemption.
* tests/testutils.h: Add common header.
* tests/commandhelper.c: Fix offenders.
* tests/cputest.c: Likewise.
* tests/domainsnapshotxml2xmltest.c: Likewise.
* tests/interfacexml2xmltest.c: Likewise.
* tests/networkxml2argvtest.c: Likewise.
* tests/networkxml2xmltest.c: Likewise.
* tests/nodedevxml2xmltest.c: Likewise.
* tests/nodeinfotest.c: Likewise.
* tests/nwfilterxml2xmltest.c: Likewise.
* tests/qemuargv2xmltest.c: Likewise.
* tests/qemuxml2argvtest.c: Likewise.
* tests/qemuxml2xmltest.c: Likewise.
* tests/qemuxmlnstest.c: Likewise.
* tests/qparamtest.c: Likewise.
* tests/sexpr2xmltest.c: Likewise.
* tests/storagepoolxml2xmltest.c: Likewise.
* tests/storagevolxml2xmltest.c: Likewise.
* tests/testutils.c: Likewise.
* tests/virshtest.c: Likewise.
* tests/xencapstest.c: Likewise.
* tests/xmconfigtest.c: Likewise.
* tests/xml2sexprtest.c: Likewise.