Add gitignore file

Add .gitignore file to make sure that the directories from the
master branch (toucan, toucan_doc, maps) don't accidentally get
committed. Remode Mermaid2 directory that shouldn't have been
added in last commit.
Publish commit da32e4d to gh-pages:

  Author: Clare O'Neill CONeill@argans.co.uk
  Date: Thu May 15 10:31:20 2014 +0100
  Refactor to reflect name change to TOUCAN