Release 1.0.0.rc1
Merge branch 'master' of github.com:mojombo/jekyll

* 'master' of github.com:mojombo/jekyll:
  Moving comparison for PostUrl tag to the PostComparer class
  Fail if destination directory for jekyll new exists and is not empty. Fixes #981.
  Remove code duplication: #write in Page and Post is the same.
--plugins can now accept plugin directories. Fixes #993.