Tremor README

[0] http://svn.xiph.org/trunk/Tremor/
Original Tremor implementation, used in Hedgewars until the Tremor devteam branched the internal Ogg implementation.
More details: http://lists.xiph.org/pipermail/tremor/2010-August/001650.html

[1] http://svn.xiph.org/branches/lowmem-no-byte/Tremor/
A Tremor variant, suited for low memory devices, still contains an Ogg implementation, used in Hedgewars.

[2] http://svn.xiph.org/branches/lowmem-branch/Tremolo/
An interesting Tremor variant with a lot of ARM optimisations.