Fast cached jshint for gulp

It uses in memory stat cache, that's why lint-watch is blazing fast.

Usage:

var sources = './**/*.js';

gulp.task('lint', gp.jshintCache({ src: sources }));

gulp.task('lint-or-die', gp.jshintCache({ src: sources, dieOnError: true }));

gulp.task('lint-watch', ['lint'], function(neverCalled) {
  gulp.watch(serverSources, ['lint']);
});

Options:

• sources* -- sources for glob.src
• dieOnError -- if true, the process will die with error status 1 if lint fails. Use this for git pre-commit check.
• jshint -- options for gulp-jshint