README.md: Rename file to README
src/picolisp: Merge March 2014 miniPicoLisp updates

Include all mar14 miniPicoLisp changes (from Alex) in
src/picolisp/src

This commit retains all Alcor6L specific sections of
the code from before this commit. For eg. The WORD
symbol defined in pico.h is still called PICOLISP_WORD
since WORD is already defined in the types file from
the Atmel LLD codebase.

The merged code has been tested on at32uc3a0256. The
merge doesn't seem to be causing any problems. Only,
I can't quit my Lisp session with ctrl-Z. I'll have to
get to that in a bit.