Little Endian is not enforced for fixed64 formats and the like

[GoogleCodeExporter]

No tests done, but examining the code it seems we generally just call typecast 
in matlab, which should use the system's endianness, when writing or 
interpreting fixed64 like types. The protocol buffer standard specifies for 
little endian to be used, so encoding or parsing on a big endian machine would 
produce incorrect results.

Typecast is also used in parsing of several other types, so they might also be 
broken on a big endian system.

Original issue reported on code.google.com by [email protected] on 23 Mar 2012 at 6:14