- update dvb subsystem core
 - switched from user-land types like __u8 to u8 and uint16_t to u16
   this makes the patch rather large.
 - updated the dvr (digital videorecording) facility
 - renamed some structures, like "struct dmxdev_s" to "struct dmxdev"
 - introduced dvb_functions.[ch], where some linux-kernel specific
   functions are encapsulated.  by this, the dvb subsystem stays quite
   independent from deeper linux kernel functions.
 - moved dvb_usercopy() to dvb_functions.c -- this is essentially
   video_usercopy() which should be generic_usercopy() instead...
 - Made the dvb-core in dvbdev.c work with devfs again.
 - remove all typedefs from structs
 - remove all typedefs from enums