lib: Add initial device flashing support (node.js only)

Pure JS/CS, will be ported to also support Chrome serial and allow
flashing device directly from Flowhub app.
node microflo.js flash build/arduino/.build/nano328/firmware.hex --serial=/dev/ttyUSB1 --baudrate=57600
compiler: Add initial code for compiler service
('chrome' in window) safety checks

otherwise hoses ff
Merge pull request #56 from forresto/patch-1

('chrome' in window) safety checks
Makefile: Use own avrdude implementation for flashing

Missing auto-detection of baudrate based on MODEL, so might
need to customize the oneself. But at least now we're testing
Kill node.js addon, use Emscripten based simulator instead

Tests are passing, however those that require verifying I/O are
currently disabled. Need to add to the protocol functions for setting
fake I/O and getting notified on changes.
Update serialport dependency
Travis: Don't symlink clang executables

Seems to not be needed anymore, and caused failures
Revert "Makefile: Use own avrdude implementation for flashing"

Does not seem to work just yet
This reverts commit d55a75ff94013da4b7e1ded97d2051ab04f6a670.
simulator: Remove, integrated into Flowhub