(git|svn)_cache_setup - Display message when initializing cache (because it's slow).
Allow CMS_ROOT to be different from WEB_ROOT

Example: In drupal-clean, the root of the build is also the CMS_ROOT (eg
"buildkit/build/drupal-clean/index.php").  However, in wmff, the CMS_ROOT is
in a subdir (eg "buildkit/build/wmff/drupal/index.php").
app/config/wmff - Add example based on wmff's git-submodule structure
app/config/wmff - Add install-theme.php
civibuild - Reset IS_INSTALLED

Example use case:

```
civibuild download foo
civibuild install foo
civibuild download foo --force
civibuild install foo
```

For command 4 to run correctly, command 3 must unset IS_INSTALLED.
app/config/wmff - Work-around to support MySQL on alternate ports
app/config/wmff - Fixes for install.sh
Merge pull request #56 from totten/master-wmff

Add "wmff" config type