Always use the unaligned variants of GST_READ_UINT* and GST_WRITE_UINT* as it's too...

Always use the unaligned variants of GST_READ_UINT* and GST_WRITE_UINT* as it's too easy to break the ISO C strict al...

Original commit message from CVS:
* docs/gst/gstreamer-sections.txt:
* gst/gstutils.h:
Always use the unaligned variants of GST_READ_UINT* and GST_WRITE_UINT*
as it's too easy to break the ISO C strict aliasing rules with simple
casts to the corresponding type and this would introduce hard to debug
bugs. Fixes bug #545714.
API: Add GST_READ_UINT24_(LE|BE) and GST_WRITE_UINT24_(LE|BE).