Fix parsing of header when not separated with double-newlines

Close #94
Merge pull request #95 from mishoo/issue-94

Fix parsing of header when not separated with double-newlines
Add JSHint support.

Use `npm run check` or `npm run lint`.
Fix a few JSHint warnings.
.jshint.rc: Enable curly rule.
Get rid of node.js v0.9 from travis; it was buggy and not stable.
Reindent markdown.js.