Fix reopened tooltip getting closed by timer
Fix reopened tooltip getting closed by timer

Cases:
- enabled tooltip gets closed after disable + re-enable
- disabled tooltip gets closed after create + re-hover

Superfluous clearTimeout calls in the regular case after timeout have no
effect.

saesh/brouter-web,nrenner/brouter-web,saesh/brouter-web,saesh/brouter-web,nrenner/brouter-web,nrenner/brouter-web