[rbp/omxplayer] When reencoding thumbnails preserve orientation

Currently reencoded thumbnails are displayed without original orientation flag applied.
However we can write the Orientation field of IFD0 data, which means the cached thumbnail will be displayed correctly when decoded
[rbp/omxplayer] Never trust pts in avi files

Currently we play unpacked avi files with slight stutters. The pts values are incorrect and are actually dts values.
Set the flag that says ignore pts.