TODO

* Do not show error on empty line -- RESOLVED
* Add log posibility
    * Add support for UP_ARROW, DOWN_ARROW, TAB...
* Remove arguments inside the functions  -- HALF-DONE
* Example for Arduino
* Example for DAVE (using dbg_serial and usb_vcom)
* Compare getopt to gnu's getopt (at least the behaviour) -- HALF-DONE
* Simplify strings to make customization simpler
* Create a clear interface (static library + customizable my_commands)
* Measure the size of the library (in terms of used memory)
* Allow the user handle '-h' option in auto-help mode
* Write documentation
* Use docblockr to make doxygen-compatible documentation
* Give control of the terminal to a command
* Use Ctrl+C to stop a command which is executing
* Include that code to get compatibility with C++

* Create several versions of UniversalShellBuilder (Arduino / PIC / XMC / DAVE)?
* Create a 'cat' example to demonstrate the use of non-option arguments -- DONE
* Another bug in getopt... (when example -ab adsf -c adfs) -- RESOLVED
* Easy non-option arguments handling -- DONE
* Modify default_cmd_error to avoid string unions
* Give support to -N options (where N is a number)