docs(build): add a link to Chrome extension reloader with hotkey
refactor(vk_lib): remove vkCheckUpdates()

This is related to #31.
refactor(vk_lib): remove unneeded old ajax api calls
fix(chromium inject.js): provide old cross-origin ajax interface

- make GET, POST, and HEAD requests as content_script.js did
- remove jQuery, use pure js

This faces #49.
feat(build): on non-Windows envs say that Maxthon packager won't work

If OS in not Windows log that Maxthon packager only works on Windows.
fix(maxthon inject.js): provide old cross-origin ajax interface

- make GET, POST, and HEAD requests as content_script.js did
- fix permissions in def.json to allow requests to *.vk.me

This faces #49.
fix(opera inject.js): provide old cross-origin ajax interface

In inject.js listen to "message" window event, pass data to background.js
which runs via index.html and perform a request there because
UserScripts (e.g. inject.js) can't make cross-origin requests.

This faces #49.
fix(firefox inject.js): provide old cross-origin ajax interface

Make GET, POST, and HEAD requests as content_script.js did.

This finally closes #49.
fix(vk_face.js): use app.name for left menu extension item

This closes #60.
fix(vk_settings): fix quotes order, typo