initial HLint support

rebase
Merge pull request #10 from x0l/hlint

initial HLint support
Add JS support via JSHint
Merge branch 'master' into jshint

Conflicts:
	README.md
	lib/linter-map.cson
Fixed JSHint errors and increased error handling.

* Reduced the depth of the code to make it easier to reason about.
* Now properly handling errors resulting from xml parsing.
* Fixed a bug where not having any violations resulted in an error :)
* Made some variable names less confusing.
Merge pull request #11 from benjohnson/jshint

Added JSHint
Update changelog for #10 and #11
Add atom-lint-spec
Extract linter running logic to LintRunner
Fix JSHint highlight position

Related to #11.
Fix an odd animation on red violation arrows when the editor was clicked
Avoid injecting lint view to command palette
Add "Move to Next/Previous Violation"

This closes #2.
Prepare changelog for 0.4.0
Prepare 0.4.0 release
Tweak README
Improve package description
Rename file basenames
Add an OPTIMIZE comment
Minimize additional startup time of Atom caused by atom-lint