Hyphen vs Minus

As we are in many cases already using the typographical correct character (`„“”` vs. `"`) I propose using the correct minus character instead of the hyphen.

`-` <- this is a hyphen (the one next to the full stop on a German keyboard)
`−` <- this is a minus

Note the difference:
`+-` <- the hyphen is lower than the horizontal bar of the plus
`+−` <- the minus is at the same vertical position and it has got the same width (if it does not show correctly try copying it into your comment box)