Serverside Templates processor and Rewriter (shindig)

Support for:
 - ${} in text nodes and attributes
 - loops via @repeat (some @var support)
 - conditionals via @if
 - special vars:
   - Top 
   - Cur
   - Context.Index / Context.Count in loops

Not currently supported:
 - Any kind of custom tags (including <os:Html> and <os:Render>)

TODO: 
  - More unit tests for TemplateProcessor

[levik, 2009-02-11 18:11:55]

http://codereview.appspot.com/14074/diff/1/6
File
gadgets/src/main/java/org/apache/shindig/gadgets/rewrite/PipelineDataContentRewriter.java
(right):

http://codereview.appspot.com/14074/diff/1/6#newcode198
Line 198: content.addPipelinedData(key, entry.getValue());
This is the only line I added to this file

http://codereview.appspot.com/14074/diff/1/7
File
gadgets/src/main/java/org/apache/shindig/gadgets/rewrite/TemplateRewriter.java
(right):

http://codereview.appspot.com/14074/diff/1/7#newcode121
Line 121: private static boolean checkRequiredData(String requiredData,
Map<String, ?> availableData) {
TODO: handle requiredData == null

[levik, 2009-02-11 20:31:15]

added @var support, "Top" looks for top level (not parent) context

[levik, 2009-02-12 23:20:47]

Incorporated EL changes from Adam, added unit tests