Firefox: removing extra space in front of negative number is alowed only in path data, but not in transform

[deepsweet]

http://old.nabble.com/Negative-values-in-polygon-polyline-points-td27993375.html

so we can do

<path d="m10-20"/>

instead of

<path d="m10 -20"/>

but can't

<g transform="matrix(.707-.707 .707 .707 0 0)"/>

instead of

<g transform="matrix(.707 -.707 .707 .707 0 0)"/>