error reporting now reports accurately to the line.

tests/testjet.jet

@@ -10,6 +10,8 @@
  $[modified1;$[tohex]]
  <set name="complete" value="$[modified1];$[tohex]" />
  $[complete]
+ <set name="" value="xxx" />
+ the unnamed variable value: [$[]]
  ---
  $[nonexistant]
  $[%HOME]
@@ -21,7 +23,8 @@
  <set name="division" expr="5/3" />
  <set name="divisor" value="8" />
  <set name="nested" expr="(2*(4+4)/$[divisor])*32" />
- $[nested]
+ <set name="error" value="$[$x]" />
+ $[$nested]
  <set name="numbers">0123456789</set>
  <set name="lefty" expr="LEFT($[numbers],5)" />
  lefty=[$[lefty]]