In the same way we can #require ElectricImp libraries, it would be great to be able to attach our own GitHub accounts, this way we can update library code without having to copy and paste it or resort to the build api / offline tools.
There’s some fairly obvious future features this could lead to as well, such as backing-up of files to GitHub and multi-file management.
We’re not planning to do anything in this area; the online IDE is really intended for just getting started. It proves to be impossible to satisfy every developer’s requirements with a single IDE 
Instead, we’re working on building out the offline tool set - local includes, unit test/CI support, etc - as that facilitates a much better experience that each developer can customize to their way of working. Some of these tools are in test right now, contact us if you would like more information.
There’s also a command-line tool developed by community member @nightrune which several developers are using:
https://discourse.electricimp.com/discussion/4093/wrench-preprocessor-and-build-tools-for-the-electric-imp-platform
Please take a look at wrench.
https://discourse.electricimp.com/discussion/comment/22817#Comment_22817
Wrench allows local libraries with a pretty old school #include, #ifndef architecture, but its very very useful as you can build out make models from a single set of libraries locally. I do plan to add some git support later on. Closer to how golang deals with it.
Please email me if you have any questions on wrench so I can help make the tool better for the community as a whole.
Sean Sill
theblacklabcoat@gmail.com