Feature request for allowing people to change the default 
jsessionid cookie name.

This feature is needed in the following case :

Setup :
-------
- A single Apache web server fronting Tomcat servers 
  AND other proprietary web servers.
- A web applications 'A' is deployed on a Tomcat server, while another 
  web application 'B' is deployed on another proprietary web server. 
  Both applications 'A' and 'B' are accessed through the same IP or DNS 
  name, but with different context-roots.

Problem :
---------
1) A user logs in on application 'A' on a Tomcat server, and does some work.
   The id of his session is retained in a cookie, named "JSESSIONID"
2) web application A redirects the user to an application B on another, 
   proprietary, web server.
3) The user arrives on application B. The session id contained in the cookie
   is not recognized. A new one is created, which replaces the old one.
4) user returns to application A. The session id contained in JSESSIONID cookie
   is the id of a session on a proprietary web server, which obviously does not
   correspond to any session on Tomcat. Thus, Tomcat is unable to retrieve the
   user's session. Session is lost.

In some case, this problem can be fixed by setting the 'emptySessionPath'
attribute to 'false' in Tomcat's server.xml. This will make all JSESSIONID 
cookies target '/context' path instead of '/', and hence preserve the values
of the jessionid cookies. However, this attribute cannot be set to false in 
some scenarios, e.g. when portals are used, which require that jsessionid
cookies be transmitted across applications.

Solution :
----------
A solution is to allow people to configure the name of the jsessionid cookie,
for all applications on a given server, or for a specific application.
In the depicted scenario, this prevents the application server 'B' to overwrite 
the jsessionid cookie of the application 'A'.

Currently, changing the name of the jessionid cookie is not possible, as it is 
harcoded in the following source files (non-exhaustive list) :
 org/apache/catalina/connector/CoyoteAdapter.java (catalina.jar)
 org/apache/catalina/connector/Response.java (catalina.jar)
 org/apache/catalina/realm/RealmBase.java (catalina.jar)
 org/apache/jasper/tagplugins/jstl/Util.java (jasper-compiler.jar)
 native/common/jk_global.h (mod_jk.so)

This feature request applies (at least) to Catalina, Jasper and Native:JK.