Roboto Mono is considered variable-pitch by PuTTY in Windows

(Possibly related to or caused by #142 #160 #249)

Roboto Mono is not considered to be a monospace font in PuTTY -- which I assume is actually "in Windows" but I didn't test with other programs.

This causes it not show up in the selectable fonts list when configuring PuTTY unless the option "Allow selection of variable-pitch fonts" is selected. Additionally, PuTTY is noticeably slower in refreshing the screen when Roboto Mono is selected (as compared with Droid Mono), presumably due to its being variable pitch.