[MNG-4228] NEED ITS. This implements wagon-impl selection using 'maven.wagon.proto=implname' form of system property. Switched out extension loading to use component descriptor lookup instead of component lookup to avoid killing the system in the event that one wagon extension cannot load. This last is because something has screwed up the loading of the dav+http/s wagons, and it affects unrelated ITs.
This implementation needs ITs to verify the selectable wagon behavior, and another to verify the presence and loadability of the dav+http/s wagons.
git-svn-id: https://svn.apache.org/repos/asf/maven/maven-2/branches/maven-2.2.x@792795 13f79535-47bb-0310-9956-ffa450edef68
5 files changed
