Add bit timing class

[christiansandberg]

A class for holding bit timing parameters. This is intended to replace the various bit timing arguments in some interfaces.

Part of #614.

[codecov]

Codecov Report

Merging #615 into develop will increase coverage by 0.07%.
The diff coverage is 66.9%.

@@             Coverage Diff             @@
##           develop     #615      +/-   ##
===========================================
+ Coverage    63.91%   63.98%   +0.07%     
===========================================
  Files           63       64       +1     
  Lines         5623     5765     +142     
===========================================
+ Hits          3594     3689      +95     
- Misses        2029     2076      +47

[felixdivo]

Maybe this is a good time to add typing information to the arguments & properties.