Issue1507

On a request such as "/path?key" modjy throws a ValueError from line 42 of 
modjy_publish, which assumes that any portion of the query string between 
ampersands will contain an equals character:
http://fisheye3.atlassian.com/browse/jython/trunk/jython/Lib/modjy/modjy_p
ublish.py?r=6842#l47

Traceback (most recent call last):
  File '/usr/local/tomcat/webapps/myapp/WEB-
INF/lib/jython.jar/Lib/modjy/modjy.py', line 76, in service
  File '/usr/local/tomcat/webapps/myapp/WEB-
INF/lib/jython.jar/Lib/modjy/modjy.py', line 76, in service
  File '/usr/local/tomcat/webapps/myapp/WEB-
INF/lib/jython.jar/Lib/modjy/modjy.py', line 92, in 
dispatch_to_application
  File '/usr/local/tomcat/webapps/myapp/WEB-
INF/lib/jython.jar/Lib/modjy/modjy_publish.py', line 63, in get_app_object
  File '/usr/local/tomcat/webapps/myapp/WEB-
INF/lib/jython.jar/Lib/modjy/modjy_publish.py', line 108, in 
get_app_object_old_style
  File '/usr/local/tomcat/webapps/myapp/WEB-
INF/lib/jython.jar/Lib/modjy/modjy_publish.py', line 47, in map_uri
ValueError: need more than 1 value to unpack

This only occurs when the "callable_query_string" app invocation model
is used.

Nonetheless, modjy was definitely crashing in this scenario.

I have checked in a fix at r6951. This fixes the error, making handling
of errors in callable_query_string configurations more strict. The
checkin includes multiple unit-tests.