Rename base64 implementation to avoid name conflicts with Arduino implementation

[FabianScheidt]

I want to use this HomeKit Implementation together with a web server and came across a name conflict with the Arduino implementation of base64 encoding (here). I'm not proficient in C, so there may be a better solution for this, but I figured that simply renaming the file fixes the issue. Renaming the file in the HomeKit implementation seems to make more sense, as the Arduino standard library will always be present.

Let me know your thoughts :)

[cfurter]

+1