Remove mojo/shell and (most) service implementations

Remove mojo/shell and (most) service implementations

These are being developed in the mojo repository. Prebuilt mojo_shell
binaries can be downloaded from chromium using the
mojo/public/tools/download_shell_binary.py script.

R=ben@chromium.org

Committed: https://crrev.com/6e789f246f3ca1391340240dc274672949d2f2ff
Cr-Commit-Position: refs/heads/master@{#301583}

[Ben Goodger (Google), 2014-10-28 05:28:05]

lgtm

[jamesr, 2014-10-28 05:30:40]

Going to have to unhook some mojo app targets in component build in GN.  If you
wanna build these, use a non-component build.

[jamesr, 2014-10-28 05:57:26]

The CQ bit was checked by jamesr@chromium.org

[commit-bot: I haz the power, 2014-10-28 05:58:45]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/687433002/20001

[commit-bot: I haz the power, 2014-10-28 07:07:18]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2014-10-28 07:07:56]

Patchset 2 (id:??) landed as
https://crrev.com/6e789f246f3ca1391340240dc274672949d2f2ff
Cr-Commit-Position: refs/heads/master@{#301583}