Fixed read tag to throw exception on file error unstead of looping forever.

tests/testjet.jet

@@ -1,4 +1,4 @@
-#!./jet-2.0
+#!../jet-2.0
 <jet cgi="true" name1="localname" filterblanklines="true" trimlines="true">
  <header name="Content-Type" value="text/html" />
  <comment>This is a comment and should not show up in the output.</comment>
@@ -54,7 +54,7 @@
  <call status="rc" pgm="/usr/bin/ls" arg1="-al" name="ls" />
  $[rc]
  $[ls]
- <read file="compile" name="file" />
+ <read file="../compile" name="file" />
  $[filex]
  <whiledir path="." filename="file" fullpath="fullpath" filenamenoextension="noext" sort="true">
   $[file] $[fullpath] $[noext]

tests/testvar.jet

@@ -6,6 +6,7 @@
 <set name="1var1" value="This is another test" />
 <set name="var1var" value="Yet another test" />
 <set name="var11" value="it seems to work." />
+$[$test]
 $[$[ix]var$[ix]]
 $[var$[ix]]
 $[var$[ix]var]