* Moved cur.rkt to main.rkt, which fixes some reader issues
* Added sweet-expression tests
* Added notes about sweet-expressions to README
* Added sweet-exp as dependency to tests
Created split packages: cur, cur-lib, cur-test, cur-doc, similar to
other Racket packages, e.g., redex.
* Moved tests out of core and into cur-test
* Moved docs into cur-doc
* Moved cur implementation and libraries into cur-lib
* Added cur meta-pacakge that installs all of the above
Moved all curnel code into curnel/, and split the two kernel modules
into separate files. Now the trusted core and the module/#lang stuff are
in separate files. The #lang is now reprovided by "cur.rkt", which
should also provide core agnostic sugar.
