ignore IntelliJ editor files + refactor spec

Ignore masks based on defaults in IntelliJ source code:

http://git.jetbrains.org/?p=idea/community.git;a=blob;f=platform/util/src/com/intellij/util/io/SafeFileOutputStream.java;h=da71335d4d810662f50f5c4be75ee34f34062bc7;hb=30d5ad4dc6823df8d652b1658715f65ae780bc43