Fixed move keyword collision and made cloneable

[tsurai]

The keyword move has been added in version 0.12.0 and collides with the move Event function causing an compile error. This pull request adds the prefix is_ to all boolean Event functions in order to fix this problem.

Additionally both INotify and Event are now deriving Clone to make them usable in cloneable environments.

[hannobraun]

Thank you for this pull request!
The changes look good, however, the project won't build with the latest nightly due to rust-lang/rust#17853. Basically, all static declarations should become const.

Would you mind fixing this while you're at it? If you don't have the time, I'll just merge this as is and make the const change later myself.

[tsurai]

Thanks @hannobraun for checking the nightly build. My own rustc is only about two days old and I didn't notice that they had such a big change.
I have pushed a new commit to fix the recent change of the static keyword.

[hannobraun]

Awesome, thank you!

Development has certainly gotten a lot calmer since I started with Rust around November/December last year. That makes it all the more surprising when they sneak in a big breaking change like that :)