Make site extensions more CSM friendly

- rename extensions to siteextensions to avoid conflict with CSM 'Extensions' token
- Remove the /local/ segment so operations are top level
- Change extensions/remote to extensionfeed so it's top level
- Use PUT instead of POST for Install
- Pass the Id on the path instead of body for Install
- Support installing non-default versions
Fix extension test to match API change.
Change tab-autocomplete to behave like cmd.exe and fixes #1144 as well
Improve WebJobs tests to be able to run on more than a single instance
Update ConsoleWorker git repository
Fix WebJobs tests to pass on multiple instances scenario
Preserve the body when tranferring the request in cshtml case.

Also, return after the transfer

Fixes issues #1048, #1155
Update diagnostics settings API to be aware of specific diagnostics settings while remaining generic to accept any other settings as pass-through.