Implement optional groups

* Add optional option to the group method, defaulting to false
* Exclude optional groups from the groups to be installed
* Add --with parameter to bundle install to install a group that would
* otherwise be excluded
* Error out if a group is listed in both, --with and --without
* Add bundle_with option to capistrano task

1 files changed, 5 insertions, 1 deletions

diff --git a/man/gemfile.5.ronn b/man/gemfile.5.ronn
index 876c927380..dcd1961ab4 100644
--- a/man/gemfile.5.ronn
+++ b/man/gemfile.5.ronn
@@ -430,11 +430,15 @@ applied to a group of gems by using block form.
       gem "sqlite3"
     end
 
-    group :development do
+    group :development, :optional => true do
       gem "wirble"
       gem "faker"
     end
 
+In the case of the group block form the :optional option can be given
+to prevent a group from being installed unless listed in the `--with`
+option given to the `bundle install` command.
+
 In the case of the `git` block form, the `:ref`, `:branch`, `:tag`,
 and `:submodules` options may be passed to the `git` method, and
 all gems in the block will inherit those options.