manager and filter for .gitignore rules - Node.js library

 "ignore" is a manager, filter and parser
 for the .gitignore spec at <https://git-scm.com/docs/gitignore>,
 implemented in pure JavaScript.
 .
  * Standalone module, much simpler than e.g. "fstream-ignore".
  * Only contains utility methods
    to filter paths according to the specified ignore rules.
  * Never tries to discover ignore rules
    by traversing directories or fetching from git configurations.
  * Doesn't care about sub-modules of git projects.
  * Complies exactly to gitignore documentation
    at <https://git-scm.com/docs/gitignore>:
    - "/*.js" should only match "a.js", not also "abc/a.js".
    - "**/foo" should match "foo" anywhere.
    - Prevents re-including a file excluded in a parent directory.
    - Handles trailing whitespaces:
      - "a " (one space) should not match "a " (two spaces).
      - "a \ " matches "a ".
    - All test cases are verified against "git check-ignore".