Merge pull request #26 from alice/master

Modify AuditRule to walk the DOM tree and collect elements, using a matcher method on each audit rule, rather than having each audit rule responsible for selecting all relevant nodes.
Use element.ownerDocument.evaluate
element.querySelector doesn't return an array
Use grunt to compile
Revert audits
Update README with build information
updated axs_testing.js generated file
use scope.ownerDocument.evaluate instead of document.evaluate
node.ownerDocument returns null if node is a document
fix node type checking
Update README with more details on installing dependencies.
Remove Makefile and axs_testing
Merge branch 'grunt' of https://github.com/alice/accessibility-developer-tools into grunt
merge changes
arrgh newlines
Add permalink to github revision in generated file.
Fix indenting
Point to /tree instead of /commit on github; use full commit hash
Merge pull request #29 from alice/grunt

Use grunt to build, remove Makefile and gen/axs_testing.js
Add gen/ to .gitignore