ignore: combine readignorefile and _ignorefile _ignorefile did nothing except open the file. Let's combine it with readignorefile for simplicity. This will make it easier to rename and move to match.py in upcoming patches.

ignore: move bad file handling out of readignorefile In preparation for moving readignorefile to match.py to make it more generally usable, let's move the bad ignore file handling up to the ignore specific logic.