Fix for issue #110

Every time, a z-wave device sends a "I'm ready"-Event, the local map entry of this node is re-written.
Thats because a too late abort statement, which should check, if this node is already initialized. As an effect, the Device object instance is getting lost and the `value changes`-Event can't be handled anymore.
Ignoring all project files of Jetbrains IntelliJ IDEA and WebStorm
Code cleanup for Z-Wave

 - Use callback in gateway-openzwave to be able to log errors.
 - Codestyle: Use more speaking variable than just `f` for a map of callback handlers.
Merge pull request #257 from sja/ignore-intellij-files

Ignoring all project files of Jetbrains IntelliJ IDEA and WebStorm
Merge pull request #256 from sja/fix-issue-110

Fixes #110 - that's very fancy sleuthing... thanks!
Merge pull request #258 from sja/zwave-cleanup

many thanks. i've merged and then done a very small amount of cosmetic editing for style consistency.
cube sensors poll once a minute
zwave: cosmetic editing for style consistency