The keys of entries in a VMX file are case insensitive. Both scsi0:1.fileName
and scsi0:1.filename are valid. Therefore, make the conf parser compare names
case insensitive in VMX mode to accept every capitalization variation.
Also add test cases for this.
* src/xen/xm_internal.c (xenXMConfigGetULong): Remove useless and
misleading test (always false) for val->str == NULL before code that
always dereferences val->str. "val" comes from virConfGetValue, and
at that point, val->str is guaranteed to be non-NULL.
(xenXMConfigGetBool): Likewise.
* src/util/conf.c (virConfSetValue): Ensure that vir->str is never NULL,
not even if someone tries to set such a value via virConfSetValue.
Replace free(virBufferContentAndReset()) with virBufferFreeAndReset().
Update documentation and replace all remaining calls to free() with
calls to VIR_FREE(). Also add missing calls to virBufferFreeAndReset()
and virReportOOMError() in OOM error cases.
