Allow OLED orientation change

[ProfessorKa0Z]

1. The orientation of an OLED created in config.h can be changed by adding
   #define FLIP_OLED
   to config.h.

2. Displays created by HAL can be changed by adding the optional parameter Orientation::flipped, e.g.:
   HALDisplay<OLED>::create(1, 0x3d, 132, 64, Orientation::flipped);

3. Since the HALDisplay::create constructors are shared between OLED and LCD displays, an unused default orientation parameter was added to the LCD constructors in LiquidCrystal_I2c.

4. config.example.h and myHal.cpp_example.txt illustrate use of the new options.