RFR: Add tool for importing webrev patches

[Jorn Vernee via github.com]

The pull request has been updated with a complete new set of changes (possibly due to a rebase).

----------------

Commits:
 - db1e37a7:	Reimplement webrev apply on top of the Repository API
 - 6bf09b1c:	Moved wimport functionality to be under webrev apply
 - 7c9df222:	- Specify -f option takes a path to a .patch file
			- Add missing space between }else
			- Move initializing of path variable inside of if block
 - 66c5dcc2:	Wimport prototype

Pull request:
https://git.openjdk.java.net/skara/pull/32

Webrev:
https://webrevs.openjdk.java.net/skara/32/webrev.04

Updated full patch:
https://git.openjdk.java.net/skara/pull/32.diff

Fetch command:
git fetch https://git.openjdk.java.net/skara pull/32/head:pull/32