Merge pull request #29 from RoboticsBrno/debug_uart Implement DebugLink, some refactoring

Re-implement _exit to handle abort()

Start FreeRTOS scheduler

Use StreamBuffer and wait for empty space in DebugLink

Remove v1.1 BSP preparation

Fix buffer in DEBUG_HEX

hw: add middle battery voltage (with overvoltage protection) to the power input terminal block (replaced by 3-pin)

hw: remove resistor between STM and ESP enable

hw: fix power button function without battery connected (only in schematic)

hw: fix power circuit capacitors value