Make it obvious to 'dumpxml' readers what unit we are using,
since our default of KiB for memory (1024) differs from qemu's
default of MiB; and differs from our use of bytes for storage.

Tests were updated via:

$ find tests/*data tests/*out -name '*.xml' | \
  xargs sed -i 's/<\(memory\|currentMemory\|hard_limit\|soft_limit\|min_guarantee\|swap_hard_limit\)>/<\1 unit='"'KiB'>/"
$ find tests/*data tests/*out -name '*.xml' | \
  xargs sed -i 's/<\(capacity\|allocation\|available\)>/<\1 unit='"'bytes'>/"

followed by a few fixes for the stragglers.

Note that with this patch, the RNG for <memory> still forbids
validation of anything except unit='KiB', since the code silently
ignores the attribute; a later patch will expand <memory> to allow
scaled input in the code and update the RNG to match.

* docs/schemas/basictypes.rng (unit): Add 'bytes'.
(scaledInteger): New define.
* docs/schemas/storagevol.rng (sizing): Use it.
* docs/schemas/storagepool.rng (sizing): Likewise.
* docs/schemas/domaincommon.rng (memoryKBElement): New define; use
for memory elements.
* src/conf/storage_conf.c (virStoragePoolDefFormat)
(virStorageVolDefFormat): Likewise.
* src/conf/domain_conf.h (_virDomainDef): Document unit used
internally.
* src/conf/storage_conf.h (_virStoragePoolDef, _virStorageVolDef):
Likewise.
* tests/*data/*.xml: Update all tests.
* tests/*out/*.xml: Likewise.
* tests/define-dev-segfault: Likewise.
* tests/openvzutilstest.c (testReadNetworkConf): Likewise.
* tests/qemuargv2xmltest.c (blankProblemElements): Likewise.

The MAC addresses with 00:50:56 prefix are split into several ranges:

  00:50:56:00:00:00 - 00:50:56:3f:ff:ff  'static' range (manually assigned)
  00:50:56:80:00:00 - 00:50:56:bf:ff:ff  'vpx' range (assigned by a VI Client)

Erroneously the 'vpx' range was assumed to be larger and to occupy the
remaining addresses of the 00:50:56 prefix that are not part of the 'static'
range.

00:50:56 was used as prefix for generated MAC addresses, this is not possible
anymore, because there are gaps in the allowed ranges. Therefore, change the
prefix to 00:0c:29 which is the prefix for auto generated MAC addresses anyway.

Allow arbitrary MAC addresses to be used and set the checkMACAddress VMX option
to false in case the MAC address doesn't fall into any predefined range.

* docs/drvesx.html.in: update website accordingly
* src/esx/esx_driver.c: set the auto generation prefix to 00:0c:29
* src/esx/esx_vmx.c: fix MAC address range handling and allow arbitrary MAC
  addresses
* tests/vmx2xml*, tests/xml2vmx*: add some basic MAC address range tests

* tests/.gitignore: ignore new test binaries
* tests/Makefile.am: add new tests
* tests/esxutilstest.c: test esxVMX_IndexToDiskName()
* tests/vmx2xmldata/*: config files for the VMX to domain XML test
* tests/vmx2xmltest.c: test the VMX to domain XML mapping
* tests/xml2vmxdata/*: config files for the domain XML to VMX test
* tests/xml2vmxtest.c: test the domain XML to VMX mapping