Issue #1168758 by helmo | acrollet: Optionally add --include-vcs argument when using drush rsync to sync remote platform.

We want to be able to block unwanted Drush hooks from firing, especially those in
extensions where the front-end module is not enabled. To do so, we need to know
which Hosting Features are enabled very early in the Drush bootstrap process, since
blocking the unwanted hooks from firing is accomplished with hook_drush_load()'s.

this is important for SSL certificates which may be symlink to files
that are unreadable by Aegir (which is fine, as Apache can read them
because it starts as root).

I assume the impact on other uses of ->exists() will be negligible.

See #2046249.

Conflicts:
	provision.file.inc

this code is not present in core's settings.php since at least Drupal 5.23

it seems this was just incorrectly done: the _config entry wasn't used
as an array while $configs is an array of arrays.

since _config is private I feel safe in changing the way it is
structured and used internally, and externally the API doesn't really
change, it just works. :)

this is to fix the regression introduced in e918bcc8, see #2000038

Move generated platform drushrc.php to sites/all/drush, since that's where Drush looks for them now.

Issue #1083366 by jmcclelland, helmo, EugenMayer, cschaub, gmania: Fixed Make the spokes authoritative for files/ and private/ directories.

Issue #1681904 by helmo, Jon Pugh, tom friedhof: Added Ability to configure a url to redirect to in site configuration.

Issue #1471928 by Steven Jones: Fixed provision-save: Unknown options: --context_type(), --platform, --server, --db_server(), --profile, --client_name(), --aliases.