Remove outdated build scripts.

Only used on the 2.9.x series:

    /code/jenkins-config grep -R epfl-build .
    ./jobs/scala-nightly-checkinit-2.9.x/config.xml:      <command>./tools/epfl-build 2.9.x -Xcheckinit</command>
    ./jobs/scala-nightly-main-2.9.x/config.xml:./tools/epfl-build 2.9.x &amp;&amp; ./tools/epfl-publish 2.9.x

    /code/jenkins-config grep -R epfl-publish .
    ./jobs/scala-nightly-main-2.9.x/config.xml:./tools/epfl-build 2.9.x &amp;&amp; ./tools/epfl-publish 2.9.x
Remove tools/updatescalacheck

We no longer maintain a fork.
Remove tools/test-renamer

It delivered us the terser 't1234' naming convention for test
cases. Its work is done.

This commit does the bidding of the script's author:

> Despite its shameful hackiness, checked in for posterity.
> It'll live on forever in the git history; then I can remove it.
Remove tools/remotetest

I suggest using the scala-checkin-manual Jenkins job instead.
Remove tools/*{cp, _scala, _scalac}, and tools/*pickled

The scripts to fire up a compiler or REPL from build products
have bitrotted just enough to get rid of them. They do not
include the correct JLine, nor the scala modules.

I've also removed showPickled and diffPickled which were
based on these, and were also based on some code in
ShowPickled that no longer exists since 48cc8b4.