Syntax editor: select subset of available languages

Also added a basic readme file with a list of todo's

src/www/syntax-editor/README.md

@@ -0,0 +1,32 @@
+# GF web-based syntax editor
+
+John J. Camilleri  
+November 2012
+
+An improved version of the [old syntax editor][1].
+
+[1]:http://www.grammaticalframework.org/~meza/restWiki/editor.html
+
+## Notes
+
+Tested with latest Chrome and Firefox.
+
+## TODO
+
+- Enter string/float/int literals
+- UI issue with DisambPhrasebookEng
+- more prominence to Disamb-linearizations
+- ambiguity: (optionally) parse all the resulting linearizations/variants and point out those which are ambiguous
+- random-generate a non-empty tree as a starting point
+- try to retain subtree when replacing node
+- add undo/redo (or back/forward) navigation
+- structure the set of fridge magnets some more. Even though they
+are alphabetically sorted, it's difficult to find the one that I want,
+maybe put a newline before the magnet whose first letter is different
+with respect to the previous magnet
+- The formal-looking funs and cats are not linked/aligned to the linearizations.
+Maybe a possible UI could be where the user is
+clicking on the linearization (in a chosen language) and the tree is
+drawn under it (from top to bottom, not from left to right as
+currently). So that the alignment of words to functions is always
+explicit. But maybe this is not doable.