Issue 140 - Proposal For Vote

Issue 140 - Until Activity

Proposal: Add an <until> activity to BPEL

Rationale: This is one of those classic control structures that just 
keeps on proving its utility.

Add new section:

12.x Until

The Until activity supports repeated performance of a specified 
iterative activity. The iterative activity will continue to be performed 
so long as after it executes the given Boolean <until> condition holds true.

<until standard-attributes>
       standard-elements
       activity
       <condition expressionLanguage="anyURI"?>
          ... bool-expr ...
       </condition>
</until>