Fix #570
Merge pull request #571 from dmp42/get-source-null

Fix #570
Docs: Add list of known integrations
Testing: Move ESLintTester to be external dependency (fixes #480)
Merge pull request #569 from eslint/tester

Testing: Move ESLintTester to be external dependency (fixes #480)
Docs: Updated documentation for developing rules
Docs: Add docs for no-implied-eval (refs #562)
Docs: Add docs for no-new-object (refs #562)
Docs: Add docs for no-new-wrappers (refs #562)
Fix: Misspelling in no-return-assign message
Docs: Add docs for no-return-assign (refs #562)
Docs: Add docs for no-undef-init (refs #562)
Docs: Add docs for no-underscore-dangle (refs #562)
Rename: regex-spaces to no-regex-spaces
Docs: Add docs for no-regex-spaces and all doc errors now break build (closes #562)
Fix: no-cond-assign shouldn't throw error when there's a for loop with an empty conditional (fixes #53)
Build: Add perf test
Added Emacs/Flycheck integration
Merge pull request #575 from rassie/patch-1

Added Emacs/Flycheck integration
New Rule: no-lone-blocks (fixes #512)

Removed extra down-traversal in favor of looking up one level at
ancestors and changed config from warning to error to incorporate
PR feedback.