Add v1.4.2 to History.markdown
Add 1.4.2 release post
Add link to 'a regression' in 1.4.2 release post
Rakefile's site:releases:new should use 'release' variable instead of 'version' function to specify version in YAML front-matter
Merge pull request #1836 from jekyll/update-history-with-v1.4.x

Update `master` with v1.4.x changes
Update history to reflect merge of #1836