Provide separate input for exclude regex

[variar]

I've tested this feature, and it does helps my work, thank you!
But I think it still not so convenient to write the pattern in this mode and can not co-work with "add to search". Just imagine some optimization idea:

• one include regex window and one exclude regex window, exclude window is only opened if the mode is on.
• provide "add to include search" and "add to exclude search" .

Originally posted by @xaljer in #320 (comment)