Unified .json translation files for all applications:
- There are now calls from apps/template.soy to apps/*/template.soy.
- A single set of {en,keys,qqq}.json files is created.
- I combined the existing apps/*/*.json files into apps/*.json, increasing
  the number of *.json files in the apps directory but eliminating the ones
  in the apps/* directories.
- Each app gets its .js files in its generated/ directory, as before.
- Note that every app has every .js file.  Right now, most are trivial
 (the same as en.json), but that will quickly change when we put these
 in translatewiki.
- The build process is given in apps/template.soy.
- The script json_to_js.py now takes multiple template files as inputs.
- Added "IBID" (case-insensitive), which should be used for descriptions of duplicated messages.  Otherwise, xlf_to_json.py flags messages with the same keyword and different descriptions.
TODO: Make MOOC branch work with changed json_to_js.py

R=neil.fraser@gmail.com

Review URL: https://codereview.appspot.com/12078044

git-svn-id: http://blockly.googlecode.com/svn/trunk@1171 c400ca83-b69d-9dd7-9705-49c6b8615e23
Made changes to puzzle/generated/*.js due to r1770
(changes to puzzle/template.soy).

Review URL: https://codereview.appspot.com/12188043

git-svn-id: http://blockly.googlecode.com/svn/trunk@1172 c400ca83-b69d-9dd7-9705-49c6b8615e23