Some DVB drivers do not work properly with ROLLOFF_AUTO and fail to tune when requested.
By allowing to override the default setting tuning to these DVB-S2 channels does work.
According to /usr/include/linux/dvb/frontend.h (DVBAPI version 5 and above) the default
value for ROLLOFF is ROLLOFF_35 iso ROLLOFF_AUTO.

- ROLLOFF_35 is now default when -R <35|20|25|0=auto> option is not given

Some DVB drivers do not work well with FEC_AUTO. This option allows
to set the FEC Inner manually.

Default value: 999 (FEC_AUTO)

* dvblast.c: Fix segfault with buffer overflow and -d option (thanks testking !) * ALL: Fix trailing whitespaces/tabs.

We're in non-blocking mode, so the kernel will deliver less than 50
automatically. Note: one DMA cycle might provide upto 350 TS packets
(64 kByte)