Improve signature detection, so that lines with delimiters in the middle of the line don't get interpreted as beginning of signature.
Revert "Improve signature detection, so that lines with delimiters in the middle of the line don't get interpreted as beginning of signature."

This reverts commit 1e8a06419dee133c51203edafd378266973bc2ca.
Improve signature delimiter regexp so that dashes/underscores/etc in the middle of text don't get interpreted as beginning of signature.
merge pr
fix the regex to ensure the dashes are in front