* configure.in: add new --with-udev, disabled by default, and requiring
libudev > 145
* src/node_device/node_device_udev.c src/node_device/node_device_udev.h:
the new node device backend
* src/node_device/node_device_linux_sysfs.c: moved node_device_hal_linux.c
to a better file name
* src/conf/node_device_conf.c src/conf/node_device_conf.h: add a couple
of fields in node device definitions, and an API to look them up,
remove a couple of unused fields from previous patch.
* src/node_device/node_device_driver.c src/node_device/node_device_driver.h:
plug the new driver
* po/POTFILES.in src/Makefile.am src/libvirt_private.syms: add the new
files and symbols
* src/util/util.h src/util/util.c: add a new convenience macro
virBuildPath and virBuildPathInternal() function
