syntax: 'var'->'let' 'function'->'func'

- 'var' has some weird scoping connotations with users of JS. better to change it to 'let', which will decide whether to make the variable a local or a global
- 'func' looks visually appealing lol
- some minor refactoring done in cparse.c

examples/getters_setters.cosmo

@@ -1,4 +1,4 @@
-var object = {
+let object = {
     __setter = [
         "field1" = function(self, val)
             print("setter for field1 called!")