This also fixes a NULL-deref of virtualDev in esxVMX_ParseSCSIController
found by Jim Meyering.

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.

esxVMX_IndexToDiskName handles indices up to 701. This limit comes
from a mapping gap in virDiskNameToIndex:

  sdzy -> 700
  sdzz -> 701
  sdaaa -> 728
  sdaab -> 729

This line in virDiskNameToIndex causes this gap:

  idx = (idx + i) * 26;

Fixing it by altering this line to:

  idx = (idx + (i < 1 ? 0 : 1)) * 26;

Also add a new version of virIndexToDiskName that handles the inverse
mapping for arbitrary indices.

* src/esx/esx_vmx.[ch]: remove esxVMX_IndexToDiskName
* src/util/util.[ch]: add virIndexToDiskName and fix mapping gap
* tests/esxutilstest.c: update test to verify that the gap is fixed

VMware uses two MAC address prefixes: 00:0c:29 and 00:50:56. The 00:0c:29
prefix is used for ESX server generated addresses. The 00:50:56 prefix is
split into two parts. MAC addresses above 00:50:56:3f:ff:ff are generated
by a vCenter. The rest of the 00:50:56 prefix can be assigned manually.
Any MAC address within the 00:0c:29 and 00:50:56 prefix can be specified
in a domain XML config and the driver will handle the details internally.

* src/esx/esx_vmx.c: fix MAC address formatting
* tests/xml2vmxdata/*: update test files accordingly

In commit 3c80fac2 'vmxnet3' handling
was added to esxVMX_ParseEthernet(), but not to the inverse function
esxVMX_FormatEthernet().

A character device's target (it's interface in the guest) had only a
single property: port. This patch is in preparation for adding targets
which require other properties.
Since this changes the conf type for character devices this affects
a number of drivers:

* src/conf/domain_conf.[ch] src/esx/esx_vmx.c src/qemu/qemu_conf.c
  src/qemu/qemu_driver.c src/uml/uml_conf.c src/uml/uml_driver.c
  src/vbox/vbox_tmpl.c src/xen/xend_internal.c src/xen/xm_internal.c:
  target properties are moved into a union in virDomainChrDef, and a
  targetType field is added to identify which union member should be
  used. All current code which touches a virDomainChrDef is updated both
  to use the new union field, and to populate targetType if necessary.

This allows to use domain-xml-from-native with VMX files that reference
unavailable datastores.

* src/esx/esx_vmx.c: fallback to the preliminary name if the datastore
  cannot be found

An inaccessible datastore has no valid URL property so don't
access its URI property.

* src/esx/esx_vi.c: esxVI_LookupDatastoreByName(): check if datastore is
  accessible before accessing its URL property
* src/esx/esx_vmx.c: update to changed datastore properties

* src/esx/esx_util.[ch]: remove esxUtil_EqualSuffix()
* src/esx/esx_driver.c, src/esx/esx_vmx.c: replace esxUtil_EqualSuffix()
  with virFileHasSuffix()

A given domain XML gets converted to a VMX config, uploaded to the host
and registered as new virtual machine.

* src/esx/esx_driver.c: refactor datastore related path parsing into
  esxUtil_ParseDatastoreRelatedPath()
* src/esx/esx_util.[ch]: add esxUtil_ParseDatastoreRelatedPath()
* src/esx/esx_vi.[ch]: add esxVI_Context_UploadFile(), add datastores to
  the traversal in esxVI_BuildFullTraversalSpecList(), add
  esxVI_LookupDatastoreByName()
* src/esx/esx_vi_methods.[ch]: add esxVI_RegisterVM_Task()
* src/esx/esx_vi_types.c: make some error message more verbose
* src/esx/esx_vmx.[ch]: add esxVMX_AbsolutePathToDatastoreRelatedPath()
  to convert a path into a datastore related path, add esxVMX_ParseFileName()
  to convert from VMX path format to domain XML path format, extend the other
  parsing function to be datastore aware, add esxVMX_FormatFileName() to
  convert from domain XML path format to VMX path format, fix VMX ethernet
  entry formating
* tests/esxutilstest.c: add test for esxUtil_ParseDatastoreRelatedPath()
* tests/vmx2xmldata/*: update domain XML files to use datastore related paths
* tests/xml2vmxdata/*: update domain XML files to use datastore related paths,
  update VMX files to use absolute paths

Extend and cleanup the VMX to domain XML mapping. Add the domain XML to
VMX mapping functions.

* src/esx/esx_driver.c: add esxDomainXMLToNative()
* src/esx/esx_vmx.[ch]: add esxVMX_SCSIDiskNameToControllerAndID(),
  esxVMX_IDEDiskNameToControllerAndID(), esxVMX_FloppyDiskNameToController(),
  esxVMX_GatherSCSIControllers(), add basic handling for the VMX guestOS entry
  to distinguish between i686 and x86_64, make SCSI virtualDev VMX entry
  optional as it should be, map the VMX networkName entry to the domain XML
  interface bridge name, add basic mapping for serial devices in pipe mode,
  add several esxVMX_Format*() functions

Add the virStrncpy function, which takes a dst string, source string,
the number of bytes to copy and the number of bytes available in the
dest string.  If the source string is too large to fit into the
destination string, including the \0 byte, then no data is copied and
the function returns NULL.  Otherwise, this function copies n bytes
from source into dst, including the \0, and returns a pointer to the
dst string.  This function is intended to replace all unsafe uses
of strncpy in the code base, since strncpy does *not* guarantee that
the buffer terminates with a \0.
Signed-off-by: NChris Lalancette <clalance@redhat.com>

* src/esx/esx_vmx.c: add it to the list of accepted devices when
  parsing the Ethernet section.

* src/esx/esx_vmx.c: add an extra type of addressType beside 'static'
  and 'generated', 'vpx' indicates that the MAC address was generated
  by a vCenter.

While trying to remove uses of unsafe strncpy in the tree, I came
across a couple of usages in the ESX driver.  To my eyes, the snprintf
replacements do the same thing in less code, and are also safer.
Signed-off-by: NChris Lalancette <clalance@redhat.com>
Tested-by: NMattias Bolte <matthias.bolte@googlemail.com>

* src/esx/esx_driver.c src/esx/esx_vi.[ch] src/esx/esx_vmx.[ch]:
  adds version checking for GSX 2.0, allows to pass a specific port
  for the connection and also add a new specific gsx scheme for
  easier connections to GSX hosts

* src/esx/esx_driver.c src/esx/esx_vi.c src/esx/esx_vi.h
  src/esx/esx_vmx.c src/esx/esx_vmx.h: extend the VI API version checks
  to accept version 4.0 and takes care of the virtualHW.version change
  from 4 to 7.

* src/esx/esx_*.[ch]: the driver, uses a remote minimal SOAP client
  to talk to the VI services on ESX nodes.
* configure.in include/libvirt/virterror.h src/Makefile.am src/driver.h
  src/libvirt.c src/virterror.c: glue in the new driver