A+/Promises-compatible calls

[devlato]

Hey guys,

maybe let's develop a new version that will be Promise-based?
I could help doing some pull requests etc.

[57uff3r]

Hi there! Unfortunately I don't have time for that now. But you can do a heavy lift and send your pull requests with code, and I'll help with documentation and mb with tests.

Promises sound like good idea to implement.