* daemon/libvirtd.c: Set custom driver module dir if the current
  binary name is 'lt-libvirtd' (indicating execution directly
  from GIT checkout)
* src/driver.c, src/driver.h, src/libvirt_driver_modules.syms: Add
  virDriverModuleInitialize to allow driver module location to
  be changed
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>