In preparation for a future patch adding new virFile APIs.

* src/util/files.h, src/util/files.c: Move...
* src/util/virfile.h, src/util/virfile.c: ...here, and rename
functions to virFile prefix.  Macro names are intentionally
left alone.
* *.c: All '#include "files.h"' uses changed.
* src/Makefile.am (UTIL_SOURCES): Reflect rename.
* cfg.mk (exclude_file_name_regexp--sc_prohibit_close): Likewise.
* src/libvirt_private.syms: Likewise.
* docs/hacking.html.in: Likewise.
* HACKING: Regenerate.

To avoid regressions, we let callers specify whether to require a
minor and micro version.  Callers that were parsing uname() output
benefit from defaulting to 0, whereas callers that were parsing
version strings from other sources should not change in behavior.

* src/util/util.c (virParseVersionString): Allow caller to choose
whether to fail if minor or micro is missing.
* src/util/util.h (virParseVersionString): Update signature.
* src/esx/esx_driver.c (esxGetVersion): Update callers.
* src/lxc/lxc_driver.c (lxcVersion): Likewise.
* src/openvz/openvz_conf.c (openvzExtractVersionInfo): Likewise.
* src/uml/uml_driver.c (umlGetVersion): Likewise.
* src/vbox/vbox_MSCOMGlue.c (vboxLookupVersionInRegistry):
Likewise.
* src/vbox/vbox_tmpl.c (vboxExtractVersion): Likewise.
* src/vmware/vmware_conf.c (vmwareExtractVersion): Likewise.
* src/xenapi/xenapi_driver.c (xenapiGetVersion): Likewise.
Reported by Matthias Bolte.

Only in drivers which use virDomainObj, drivers that query hypervisor
for domain status need to be updated separately in case their hypervisor
supports this functionality.

The reason is also saved into domain state XML so if a domain is not
running (i.e., no state XML exists) the reason will be lost by libvirtd
restart. I think this is an acceptable limitation.

Add the compiler attribute to ensure we don't introduce any more
ref bugs like were just patched in commit 9741f346, then explicitly
mark the remaining places in code that are safe.

* src/qemu/qemu_monitor.h (qemuMonitorUnref): Mark
ATTRIBUTE_RETURN_CHECK.
* src/conf/domain_conf.h (virDomainObjUnref): Likewise.
* src/conf/domain_conf.c (virDomainObjParseXML)
(virDomainLoadStatus): Fix offenders.
* src/openvz/openvz_conf.c (openvzLoadDomains): Likewise.
* src/vmware/vmware_conf.c (vmwareLoadDomains): Likewise.
* src/qemu/qemu_domain.c (qemuDomainObjBeginJob)
(qemuDomainObjBeginJobWithDriver)
(qemuDomainObjExitRemoteWithDriver): Likewise.
* src/qemu/qemu_monitor.c (QEMU_MONITOR_CALLBACK): Likewise.
Suggested by Daniel P. Berrange.

Now the VMware driver doesn't depend on the ESX driver anymore.

Add a WITH_VMX option that depends on WITH_ESX and WITH_VMWARE.
Also add a libvirt_vmx.syms file.

Move some escaping functions from esx_util.c to vmx.c.

Adapt the test suite, ESX and VMware driver to the new code layout.