* src/vbox/vbox_tmpl.c: minor bug in selecting the graphics type. if the
graphics type was desktop it was assumed that display is set for it,
and thus crashed on strdup. Also adds a number of missing OOM checks.
* docs/schemas/domain.rng: augment the video model with an optional
acceleration element with optional accel2d and accel3d flags
* src/domain_conf.c src/domain_conf.h: exten the virDomainVideoDef
structure with an optional accel field, virDomainVideoAccelDefParseXML
and virDomainVideoAccelDefFormat functions to parse and serialize
the structure.
* src/vbox/vbox_driver.c: remove some old 2.5 switches and plug the
3.0 driver
* src/vbox/vbox_V3_0.c src/vbox/vbox_CAPI_v3_0.h: the driver for
VirtualBox 3.0
* src/vbox/vbox_tmpl.c: handle the new driver and add event support
* src/Makefile.am: plug in the new module