Also removed explicit platform HAL directory inclusion from platformio.ini to make sure these errors are caught by Travis in the future

Fixes Arduino IDE builds for 8-bit AVR,
misc: Adafruit NeoPixel currently incompatible with Teensy 3.5-6, blacklisted

spi.h renamed to avoid conflicts with base libraries

Added env:anet10 to platformio.ini for easy compile and upload to this board

fix from PIO corruption

For compatibility with DevIoT, until that can be solved.

- move platformio.ini out of source directory to be more consistent with 'normal' PlatformIO usage
  - facilitates IDE integration
- add related .gitignores

add BLTouch-related messages in english and (rusty) french;
add missing endstops.h in ultralcd.cpp;
fix misc. compiler warnings;
fix lsf_reset - ZERO macro can't handle a pointer as it would only memset the size of the pointer, not the size of the entire struct

Also added the new .pio-related directory to .gitignore, and a few ignores for those who use cmake.