Add an accesskey for editing

Presumably other accesskeys would be nice, but this was the one I
wanted now.
Tidy up docs to emphasize {extra,trans}clusion a bit more

They are fairly nice sauce after all.
switch ordering of edit and dash

It just seems wrong to have edit after dash.
Prevent googlebot from submitting the mover form as a GET

Doing so doesn't do anything, but it is annoying that it
tries to do it.
Change socketinfo drop to a dl and add modified time.

This makes it a bit easier to decide if you'd like to navigate
to the listed tiddlers.
Merge branch 'master' of github.com:cdent/tank
include tiddlywebplugins.extraclude in requirements
Adjust registration form slightly to "disable" username changes

This is a short term adjustment while waiting for:

* #56
* https://tank.peermore.com/tanks/tank-notes/OauthIssues
Ajdust filedrop so it works on edit page too.

For the moment it thinks the dropped thing is an image. That will
change with a bit more tweaking.

This is a start at #55
Improve filedrop handling

This correctly deals with non binary mime types by putting
the binary array buffer directly to the server, instead of
building a JSON tiddler and putting that. This works in this
case because we don't need to worry about tags and the like.

Fixes #55
add docs for dnd
Merge branch 'policymgr' of github.com:cdent/tank into policymgr