Allow multiple children to run simultaneously
let the server caller pass through environment options
Merge commit '6241e3adf341b32b3db60a9b85477cdc42d77503'
Merging git://github.com/fcheung/spork.git in, so that we can get parallel-tests+spork working again with the latest spork

Merge commit 'a34db6c44f69583a0d8f9c4e871999d56db30f99'

Conflicts:
	lib/spork/server.rb