Cleanup and document r-syntax.el

[vspinu]

A lot of stuff is going on there and I am not very sure how much of it is actually useful. It sold be useful to document here and there the actual purpose of that functionality.

• document all functions in r-syntax.el
• document the motivation behind each group of functions
• throw away parts that are not needed and reduce unnecessary creation of small functions
• get rid of reliance on dynamic scope (do byte-compile-file to see those).