Added native messaging to openWith extension.

A way to send a url from vimium-c to openWith and open it with a native os application.

Import the openWith.xpi file via the Install Addon From File... in about:addons, make sure you have the xpinstall.signatures.required flag set to false in about:config.

To receive messages from your browser, run the Python scripts (runtimes) from the native folder according to your OS.

After creating a browser (native app executable) in the extension, you can get the browser_id by requesting the browsers variable in the openWith DevTool console:

From vimium-c:

Add a custom key mapping:

map <v-openWith> sendToExtension id="openwith@darktrojan.net" raw
map vvv LinkHints.activateOpenUrl keyword="_openWith"

Add a custom search engine:

_openWith: vimium://run1/openWith#data={"type":"openUrl","browser_id":"1","url":"$s"}

Add as many variations you want.