Change the names of capabilities added by extensions

Per the discussion at http://lists.jboss.org/pipermail/wildfly-dev/2015-June/004084.html I want to remove the qualifier 'extension' from the name of capabilities provided by extensions.

In the case of JMX capabilities, I plan to insert 'management' in its place; for the others I'll just drop an element of the name. The 'managment' bit will tend to group JMX stuff with other process management related capabilities

org.wildfly.management.jmx
org.wildfly.management.jmx.remote
org.wildfly.management.http-interface
org.wildfly.management.native-interface
etc