Add cgi support

[laoshaw]

Is your feature request related to a problem? Please describe.

no, just cgi with c

Describe the solution you'd like

use tbox to write simple cgi programs in c, similar to qdecoder, libcgi,cgic

Describe alternatives you've considered

qdecoder,libcgi,cgic

Additional context

Add any other context or screenshots about the feature request here.