Include "chrome-extension" in chrome prefixes.
You can bookmark chrome-extension://... pages.  But you can't use them:
vimium sends you to the default search engine.  This commit fixes the
issue.
Merge pull request #720 from smblott-github/chrome-prefixes

Include "chrome-extension" in chrome prefixes.
Smartcase matching for vomnibar.
Vomnibar queries are case insensitive, unless the query contains a capital letter.
Clean up regexp unit tests.
RegexpCache: reorganise and improve tests.
Enter on empty vomnibar a no-op.
Merge pull request #734 from smblott-github/enter--make-enter-a-noop-in-vomnibar

Make <Enter> on an empty vomnibar be a no-op
Add link to TravisCI page to the Build Status image
Merge pull request #740 from christophermanning/add-link-to-travis-ci-image

Add link to TravisCI page to the Build Status image
Focus window the tab is in when selecting a specific tab
Move Contributing information from README to CONTRIBUTING.md
Format and add instructions for Reporting Issues to CONTRIBUTING
Merge pull request #743 from christophermanning/add_contributing_guidelines

Add contributing guidelines
Don't close link hints when shift is pressed
Merge pull request #721 from smblott-github/smartcase

Use smartcase for vomnibar queries.
Merge pull request #741 from christophermanning/issue-690

Focus window the tab is in when selecting a specific tab.
Merge pull request #744 from christophermanning/issue-697

Don't close link hints when shift is pressed
Fix #464 - Support placeholder attribute for inputs in find mode

Whereas find mode normally identifies inputs by their value, if a value
is blank, find mode will use the placeholder value instead, if it exists
Merge pull request #748 from mhchen/issue_464

Fix #464 - Support placeholder attribute for inputs in find mode
Make smartcase locale-aware.