Add more thorough tests for AJP.

Unfortunately request attributes as sent
by mod_jk JkEnvVars can not be tested,
because request.getAttributeNames() does
not return the names of Coyote request
attributes. Only getAttribute(String)
checks Coyote request attributes.

Backport of r1645488 from trunk resp. r1645908
from TC 8.


git-svn-id: https://svn.apache.org/repos/asf/tomcat/tc7.0.x/trunk@1645960 13f79535-47bb-0310-9956-ffa450edef68
Use Map instead of HashMap in RequestDescriptor.

Backport of r1645743 from trunk resp. r1645913
from TC 8.


git-svn-id: https://svn.apache.org/repos/asf/tomcat/tc7.0.x/trunk@1645964 13f79535-47bb-0310-9956-ffa450edef68
Add tests for AJP connector "requiredSecret"
feature.

Backport of r1645763 from trunk resp. r1645920
from TC 8.


git-svn-id: https://svn.apache.org/repos/asf/tomcat/tc7.0.x/trunk@1645969 13f79535-47bb-0310-9956-ffa450edef68