Reset the Pause button in case it was set to Resume.

The reported bug is functionally fixed in git version 3.7.5. The only
remaining fix to this bug is to change the Resume button back to a Pause
button, which is what this patch does.

The new_game () function was not changing the Resume button back to a
Pause button.

https://bugzilla.gnome.org/show_bug.cgi?id=693478