Rplcd

- [fix] Check invalid cursor position only when auto_linebreaks enabled (93, 109)
- [rem] Drop support for Python 3.3
- [dep] This is the last release with official Python 2 and 3.4/3.5/3.6 support

This release adds a new charmap (thanks kroesi) and fixes an initialization
bug when using the pigpio backend (thanks makslevental).

- [add] Add support for ST7066 0B charmap (95)
- [fix] pigpio: Fix initialization without `pin_contrast` (97)
- [dep] This is the last release with official Python 3.3 support

- [fix] Fix packaging bug that would result in the error message `ImportError:
cannot import name 'codecs'` (92)

Older LCDs (or LCDs that are based off the HD44780) aren't all made equal. It
appears that some don't run at the reference clock, and as such, they're in a
busy state far more often than newer or better ones; this leads to missed
sends.

This release contains a new compatibility mode that increases wait times during
writes. This should fix issues with occasionally garbled display contents. To
enable it, pass `compat_mode=True` to the `CharLCD` constructor.

Thanks lcheng1 for the fix and albedozero for testing it!

- [fix] Add compatibility mode (91, 70)

This release adds support for the pure-python `smbus2` library as an automatic
fallback for `smbus` (thanks joscha) and fixes an issue with the testsuite
(thanks bazooka07). Last but not least, the `rplcd-tests` script should now be
included as a console script when packaging RPLCD.

- [add] Support smbus2 as drop-in replacement for I2C access (90)
- [fix] Fix missing global modifier in tests (88)
- [chg] Bundle test script when packaging (82)

This release primarily includes the pigpio backend (thanks sphh!) and a few
small improvements. Among other things, you can now use the I²C backend without
having the `RPi.GPIO` library installed!

- [add] Add pigpio backend (77)
- [chg] Limit GPIO cleanup to active pins (72)
- [chg] Add better help regarding missing `numbering_mode` (80)
- [chg] Late-import of GPIO backend in compatibility wrapper (78)