Features:
- Support all SI units + derived SI units, see #39
- Tab completion for mathematical functions, units and identifiers
- A lot of new physical constants
Bugfixes:
- Fail on name clashes with units and functions, see #29
- Allow '²' and '³' to be followed by '*', see #53
- Proper handling of identifiers that start with 'e', see #51
- Fix unit parser, see #55
Changes:
- Change short form of 'byte' from 'b' to 'B', fixes #46