DSP-RPC-POSIX initial commit is in place!

I've made the initial commit for dsp->gpp RPC calls (the development had been on my personal SVN repo so far, since I didn't feel it was ready to see daylight :P)

It's nothing spectacular yet (e.g no buffer/pointer parameters or return values allowed, so only ctype and math c library calls) and you probably won't think very highly of the coding style (or the way I do things in the makefiles...) either, but it still works :)

The SVN URL is:

http://gforge.ti.com/svn/dspeasy/branches/dsp-rpc-posix

There's a readme file under the top-level rpc/ directory which should be sufficient to get started.

possible makefile/build issue: the version of LPM I was using (local_power_manager_linux_1_24_02_09) has lpm.av5T instead of lpm_linux.av5T (as was stated in the original C6Run makefiles) so I've changed that. just find/replace it the other way around in build/gpp_libs/modules/Makefile if it complains about that.

Some notes:

• I had to put away my variadic marshaller since it was causing issues with floats (why? blog post coming soon!) - all marshalling is done inside the stubs with macros. Takes more lines but it's probably a better idea in the longer run. 
• The main points of interest in terms of code would be: the files under the rpc/ directory (dsp and gpp side stubs, some additional dsp side functions), rpc_server.c and .h under build/gpp_libs (gpp unmarshalling, symbol location and execution), cio_ipc.c (gpp RPC server, inside the C6Run C I/O server) c6run.c under build/gpp_libs (extracting the embedded GPP stubs library and setting up RPC buffers).
• I'm using the C6Run C I/O transport system to pass RPC buffers back and forth, for now.
• There's some additional parts in c6run-cc to handle the --rpc switch (add the dsp stub file to the sources list, compile the gpp stubs into a dynamic link library and embed it inside the final executable)
• Custom stubs have to be hand-coded, there's no stub generator tool yet

Support for buffer parameters coming soon! (actually, if you write a GPP side stub that does allocation from CMEM or POOL, use this RPC call for allocating memory on the DSP and pass data in this buffer,
everything should work).

Comments, criticism and suggestions are very, very welcome!