fixed tag to process containers in appropriate order instead of inline.

tests/testjet.jet

@@ -21,7 +21,7 @@
  <set name="division" expr="5/3" />
  <set name="divisor" value="8" />
  <set name="nested" expr="(2*(4+4)/$[divisor])*32" />
- $[$nested]
+ $[nested]
  <set name="numbers">0123456789</set>
  <set name="lefty" expr="LEFT($[numbers],5)" />
  lefty=[$[lefty]]