added speed steps support for forward and backward command
code improvements and added ability to pass one integer argument for command
now we can turn to the left/right sharply or normally (depends on the argument)
removed dummy text and added virtualjoystick.js as submodule
added pyserial to requirements.txt
removed non minified bootstrap css files
added jquery
added jquery and some css rules
updated location of submodule "virtualjoystick"
 the python interpreter located in venv directory will be used (instead of /usr/bin/python) to ensure that on all systems the same version is used
changed completely the interface: the button set was replaced by a very nice virtual joystick