Be explicit about what we require when migrating systems

We require access to the database from the old system and we're generating posts
for Jekyll.
Use 'newer' instead of 'future'

When talking about versions of Drupal greater than 6.1, use the word newer to
indicate that those versions have already been released. The word future implies
that those versions haven't been released yet.
Remove the word 'also' when describing Typo migrations.

The use of the 'also' is out of place here. We're only talking about one thing.
Fix the link to the Homebrew wiki
Tell people to update the site not the wiki.

We want to kill the wiki with fire.
remove leading slash from page.url and post.url
Use 'from' instead of 'at'
Use 'the' instead of 'a'
Don't end an independent thought with a preposition.
always ADD a leading slash to page.url or post.url
fix tests for always-present slash
note leading slash in the docs
Moving comparison for PostUrl tag to the PostComparer class
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.
Add UTF-8 encoding where we read in YAML so it reads in UTF-8 characters properly. Fixes #836.
Use post's directory path when matching for the post_url tag
Merge pull request #989 from mojombo/docs-proofreading

Proofread and fix up the documentation
When one clones one's fork of Jekyll, one should not use the readonly git:// protocol. Instead, use SSH.
Update history to reflect merge of #989