[ospec] feat: nicer binary with support for globs (#2141)

* feat(ospec): CLI support for file-patterns and an --ignore flag

The added dependency is only used by the node.js binary - which normally only ever installed via npm/yarn anyway.

This does not interfer with ospec proper being dependencyless.

* chore(mithril): Add glob dependency needed by the ospec binary

this is only needed while ospec is inlined in the
mithril repo. As soon as ospec is split away into a
standalone npm module, this will not be required anymore.

* refactor(ospec): Use 'match' events instead of callback

Performance should be similar, but the code looks
cleaner and easier to grok.

* Misc tweaks

ospec/package.json

@@ -12,5 +12,8 @@
   "bin": {
     "ospec": "./bin/ospec"
   },
-  "repository": "MithrilJS/mithril.js"
+  "repository": "MithrilJS/mithril.js",
+  "devDependencies": {
+    "glob": "^7.1.2"
+  }
 }