A change to how APR uses user data. Now, user data is a linked list that

is retreivable using a char string.  Basically, you provide a string that
will be used as a key when you store the data.  If the key was used before,
we will overwrite the old data.  When you want to retreive your data, pass
in the same key, and we will find the data you care about.  This also makes
it harder to put user data in when creating a context, so that option has
disappeared.  It is also impossible to inherit user data from parent contexts.
This option may be added in later.  I will be documenting this VERY soon.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@83901 13f79535-47bb-0310-9956-ffa450edef68