Improvements to IR app

[atctwo]

• Updated the IR receiver so that it can be disabled, so you can still use the watch after you enable it.
• Added a Serial code thing. You can send a command over serial, and it will be processed and sent through the IR led. It uses the format cmd;<protocol>;<code>;<size>, where protocol is one of the protocols that IRRemote supports, code is the code to send, and size is the number of bits that make up the code. Here is the code that determines what protocol to use: https://github.com/atctwo/watch-II/blob/533cf599e4a79c2f1d8b1d391cc8ed155aa2edf4/main/states/state_ir_remote.cpp#L673-L692
• Updated the IR profile thing so that blank buttons don't just mirror button 0.
• The IR library used is a very modified version of a fork of IRRemote. It is included with the repository as just files, rather than as a submodule.