Tracing statistics: make all imports explicit
Tracing statistics: make all imports explicit

Using *-style imports puts a lot of things into the module's namespace,
potentially shadowing things from earlier imports. Avoiding them makes
the code more readable and robust, because you exactly know what is
imported. In theory, it also saves a tiny bit of memory and reduces
loading time. Additionally, I can use pyflakes to look over the code.

fzadow/CATMAID,fzadow/CATMAID,htem/CATMAID,htem/CATMAID,htem/CATMAID,fzadow/CATMAID,fzadow/CATMAID,htem/CATMAID