Compile error/warning exclamation mark in file list not visible if file is currently opened

[Henning Holm]

If the currently opened file contains compile errors or warning, instead of the exclamation mark the eye icon is displayed. Having many lines of code, this makes it sometimes hard to see if there are errors in the current file.

Perhaps the eye icon could be red/yellow or something like that...

[Karsten Becker]

Added color highlighting to high depending on error level