daemon: add add_sprintf

Bring the add_sprintf function for stringsbuf from the library.

(cherry picked from commit 9b501fa5c6365958de362ecaf0f4e90c147978a2)
daemon: move AUGEAS_ERROR to the common header

Other than for current aug_* API, it will be useful for further code
using augeas directly.

(cherry picked from commit abb0b47e3f1b8b86d2d39c2a91782ac5ed4b134e)
sparsify: Remove obsolete comment.

We don't need to use compat=1.1 with modern qemu, and
lazy_refcounts may be dangerous.

(cherry picked from commit e3a02c4153f3064dd9427c4044849cf77b3a3421)
daemon: lvm-filter: use augeas for setting the filter

The way to set the filter for lvm devices was to open lvm.conf, look
for uncommented "filter =" lines and replace the configuration there.
This had the issue that if there is no uncommented filter line, then the
filter cannot be changed at all; considering newer lvm2 releases ship a
sample configuration with no uncommented filter lines, then the old way
became wrong and not sufficient.

Instead, take a copy of the upstream lvm.aug lens, with a simple change
to allow parsing also negative values in configuration, and install it
in the daemon. When asking to change the lvm filter, use augeas making
sure to use this custom lens for the lvm.conf copy used within the
appliance.

(cherry picked from commit c916ea5b680776f70f21ecb224e0e2ca7031c0f4)
Add suppression for memory leak in libvirt testDomainGenerateIfnames.

See: https://bugzilla.redhat.com/show_bug.cgi?id=1135388
(cherry picked from commit 591911f4bf0c328b207f8984c78fb6ede450f692)
test-tool: stop printing the FEBOOTSTRAP_* envvars

Stop printing the FEBOOTSTRAP_* environment variables, since they are
not used anymore.

(cherry picked from commit ca9930ef164286df5075cac890f558974efe0893)
appliance: exclude a lvm2 rule on Ubuntu (RHBZ#1111662).

On Ubuntu, exclude the Ubuntu-only 85-lvm2.rules since it causes the
automatic activation of volume groups on addition or change. This
interferes with libguestfs, as vgs which are disables suddently get
enabled.

(cherry picked from commit c004e4648d2091eb217026b15eed7e041557b635)
launch: libvirt / p2v: Fix empty_element macro.

The empty_element macro was not safe when used in a "naked" if
statement such as:

  if (config->flags & FLAG_ACPI) empty_element ("acpi");

Fix the macro so it uses do { ... } while (0) to make it safe here.

(cherry picked from commit 44ca9d563a93126bd744a819dde7237d371fe1fd)
customize: fix locking accounts with passwords

When setting the password for a locked account, make sure to still write
the password after the "!!" marker, otherwise the account will have no
password.

(cherry picked from commit ba65af34357eb79e37480758416cdc4e184689aa)
Version 1.26.9.