More minor site updates (0.11 and 0.12)

Just deployed a couple of minor revisions to the site.

Changes from 0.10 to 0.11:

f0c3e9e script/deploy: fix broken symlinking in "switch" task
6ee9c8f script/deploy: use "git rev-list" to get latest tag
f207281 Remove "logout"/"login" links rather than just hiding them
9231fea Move login/logout step definitions into "sessions.rb" file
1d16082 Capybara: add step definitions for "has_css?" matcher
34835c1 Add "I am not logged in" as a synonym for "I log out"
cee31de Cucumber: fix spelling error in login feature
525c843 Capybara: add step definitions for "have_content" "within"
f6b3c7b Capybara: add debugging step (text dump)
4eae550 Cucumber: more login features
6fd6425 Update to Rails 2.3.5
89edee4 Use sendmail for mail delivery in production mode

Changes from 0.11 to 0.12:

a948fb7 Set "envelope from" on all outgoing email