filter out special/hidden files when iterating over explorers

Signed-off-by: Steven Armstrong <steven@icarus.ethz.ch>
add missing import

Signed-off-by: Steven Armstrong <steven@icarus.ethz.ch>
++changes(3.0.1)

Signed-off-by: Nico Schottelius <nico@bento.schottelius.org>
__cron should replace entrys with his id
__cron should replace entrys with his id, try 2
++changes(3.0.2)

Signed-off-by: Nico Schottelius <nico@bento.schottelius.org>
do not package .gitignore into pypi package (fixes #255)

Signed-off-by: Nico Schottelius <nico@bento.schottelius.org>