Fix <%= grunt.task.current.target %. in Multitask files. Closes gh-994.
Make all tasks asynchronous to reduce call stack. Closes gh-1026.
util.spawn "grunt" option now uses proper Node, passes Node exec options. Closes gh-980, gh-981, gh-877.
Squashed commit of the following:

commit d1fa5a92bc1ce2b8b0a2a9901aa54e6a5ea0093b
Author: PatrickJS <github@gdi2290.com>
Date:   Mon Feb 3 02:11:18 2014 -0800

    update copyright year

Closes gh-1053.
Add default array for util.spawn optional args. Closes gh-1064.
Update copyright to 2014

Closes gh-1079.