Set color in forum css for text_input and input_text

[leper]

The css classes text_input (used by the search box) and input_text (used when creating a new topic and probably used by login and new user) don't set the color attribute.

This is a problem on systems with a dark system theme and a white (or some other light) text colour. On such systems we have a white textbox with white text and it would be nice if we could explicitly set the text colour.

[bstempi]

I will attempt to find a fix and roll this into the next upgrade.