New home for WebRev tool -- will be removed from jdk forest

[Magnus Ihse Bursie]

The WebRev tool (webrev.ksh) have been moved to a separate repo in the 
code-tools project. This will make sure we have a single master copy, 
instead of several forks across all jdk versions.

The copy of webrev currently located in the jdk forests (at 
<top>/make/scripts/webrev.ksh) will be removed.

To use webrev, please clone the webrev repo in a suitable location:
hg clone http://hg.openjdk.java.net/code-tools/webrev

It is possible to clone this repository inside a jdk forest, if you 
want. The hg forest extension will treat this repo as any other repo in 
the forest. The common/bin/hgforest.sh will not know about it, however, 
and you will need to update the repo manually if using that method.

Since there exists multiple versions of the webrev script, the plan is 
to get the best part of them all and collect it into this master. If you 
have a locally modified version of webrev, please contact me so we can 
work out how to bring these enhancement to the master copy.

If you want to report bugs on WebRev, please use the CODETOOLS project 
on JBS with the component tools and subcomponent webrev.

For webrev development discussions, please use webrev-dev at openjdk.java.net.

/Magnus