[libvirt] [PATCH v2] A bunch of extensions to libxl driver

This are some additional features to libxl driver. Some of them require change in domain config structures/syntax. Details described with each patch. There are two bugfix patches for deadlock during daemon startup. Changes since v1: - dropped 'script' disk parameter patches - updated 'script' interface parameter handling - dropped PCI passthrough patches - duplicates Chunyan's work - dropped RFC: libxl: special 'stubdom-dm' emulator to use qemu in stub domain - rebased on 1.0.6+ - VIR_STRDUP - other changes described in individual patches - new patches: libxl: initialize device structures libxl: support paused domain restore in virDomainRestoreFlags libxl: support domain config modification in virDomainRestoreFlags libxl: support network device attach/detach libxl: pass ipaddr to libxl toolstack libxl: implement lifecycle actions from domain libxl: add tablet/mouse input device support