[CM] new CodeEditor and SAL 2.0

[Heinrich Taube]

i have an alpha version 3.6.0 with most of the new code editor  and  
sal2 in place. testing/feedback would be greatly appreciated!

http://camil.music.uiuc.edu/software/grace/grace-3.6.0-alpha1.zip

(ill add windows and linux builds as i get them working )

new editor features :

fast loading and highlighting even for very large files
fast motion by expression (emacs  c-m-f and c-m-b)
improved syntactic indentation for scheme and sal2
per-buffer customizations (fontsize, columns, lines, theme) saved in  
buffer comment

SAL2 is a simpler, minimalist version of Sal, basicially infix  
expressions and function calling  with a few control statements (if  
begin loop set)
to try it out use
	Help>Tutorials>Sal 2.0 Quick Tour

that will open a new code editor window in Sal2 mode with examples of  
every construct.

rewriting the code editor has been a huge undertaking and not  
everything is working yet, it seems farily stable now but expect  
problems

editor themes still in progress
only scheme and sal2 (no sal or fomus syntax yet)
no sal2 loading
no Find/Repalce
no parens matching

known editor issues:

files with tabs wont indent well unless you actually delete the  
current white space before you indent the line
evaluating region will still parse expressions
a scheme expr in first position of buffer wonnt indent right.