Add suppression for memory leak in libvirt testDomainGenerateIfnames.

See: https://bugzilla.redhat.com/show_bug.cgi?id=1135388
v2v: Fix real conversions test by setting architecture in libvirt XML.
Version 1.27.33.
edit: move windows path code to common file

Move the code handling Windows paths from virt-edit to a common file,
so that can be shared by various tools.

Mostly code motion, with a minimum touch (the additional guestfs_h*
parameter in mount_drive_letter) to make it build and work.
fish, edit: specifies whether mount Windows as readonly
fish, edit: move the exit-on-case-sensitive-error behaviour to virt-edit

Do not unconditionally exit if guestfs_case_sensitive_path, but let
windows_path still return null. Make virt-edit then check for that, and
eventually exit on its own.
cat: use the common Windows path handling code
fish: isolate file editing (w/ editor) code in own file

Move the implementation of file editing using editor to an own file, so
that can be shared by different tools.

Mostly code motion.
fish: edit: improve the editor execution

Dynamically allocate the buffer for the command, and check also its exit
status.

Improvements taken from the current implementation in virt-edit.
fish: edit: bring backup extension to file editing w/ editor

Bring the backup extension feature from the perl-like file mode
implementation, although currently not making use of it.
fish: edit: return 1 for unchanged file

Change the return value of edit_file_editor to 1, in case the editor did
not change the (temporary) file.
fish: edit: bring the fast-time-edit protection

Bring from virt-edit the small hack of putting the ctime of the
temporary file few seconds back to notice file changes also on fast
editing.
fish: edit: add perl file editing

Add the perl file editing, mostly based in the virt-edit implementation.

This introduces a mild code duplication with edit_file_editor; will deal
with it in a later commit.
edit: switch to common editing functions

Switch virt-edit to the common edit_file_editor and edit_file_perl.
fish: edit: add verbose parameter
customize: use the common perl file editing code

Wrap edit_file_perl to OCaml, and use it instead of the OCaml version
of it.
v2v: More esx:// -> vpx:// changes.

This updates commit 155a6f0482e5eeb6a763d4d31354edc5f48a1f43.
v2v: esx: Add note to documentation about being asked for the password twice.
Add support for qemu copy_on_read feature.

When drives are added with this flag, reads from the backing file are
copied into the overlay, improving performance of reads to the same
area of disk (at the expense of local storage).  This is excellent for
reading remote / slow sources like HTTP.
v2v: Use copy_on_read in the overlays.

To speed up conversions by storing everything we read during
conversion in the overlay instead of having to reread it from the
remote server during copying.

Thanks: Matthew Booth.