3.0.0

• Added support for J-Link debugger for Teensy 3.x
• New USB features, see docs
• Updated Teensyduino to 1.4.1 (issue #32)
• Updated mbed framework to 5.7.3
• Allowed overriding of PROGNAME (custom firmware name)
• Default upload tool is set to Teensy App (GUI)
• Switching between "teensy-gui" and "teensy-cli" using upload_protocol (issue #13)
• Fixed issue with floating point for printf/scanf (issue #14)
• Fixed issue with concurrent toolchains for AVR/ARM when exporting data to IDE (issue #17)