Solve GSOD when removing currently played radio service

WHen in radio mode the channelselection was always displayed you could get
a GSOD. Thanks Dima73 for reporting.
Commit a different fix for the GSOD in the radiomode

As the previous fix could get a GSOD when for example you are in the
movemode
httpstream: fix off-by-one error which might result in a segfault.
etpm: fix possible segfault

The indent was incorrect which concealed a block of memory
being used (returned) after been released. The pointer now
explicitly set to NULL prevents this.
Ensure that after start of enigma2 PositionGauge is not polled
Solve most likely a copy and paste typo around autoaudio_ddp
Avoid that InfoBarTimeshif state is shown when coming from audioselection

And possibly other instantiated infobar screens. This was intrododuced by
commit
http://sourceforge.net/p/openpli/enigma2/ci/dd50f6ce9d90eae0a513f4325a32fb7596791d35/
and solved by only doing this the first time when the InfoBar is executed.

Thanks Beeker for the early reporting
http://openpli.org/forums/topic/34480-osd-player-na-verlaten-hoofdaudiomenu/
Merge branch 'master' of git://git.code.sf.net/p/openpli/enigma2