TextFilter: improve behavior for multiple filters

[phisko]

PassFilter will now return true if all required ranges are found

The current behavior is rather inconsistent: given "Some fancy sentence" as text, PassFilter will:

• return true if the filter is fancy,-sentence
• return false if the filter is -sentence,fancy
• return true if the filter is fancy,random

From my experience, this isn't what end users expect when using a search filter.

This also simplifies the code, and removes the CountGrep mechanism.

[ocornut]

Seems similar to #2435

[phisko]

Indeed, for some reason #2435 didn't come up in my search results before implementing this, but it's a more complete version of this (although it doesn't simplify the code quite as much). From what I can see you're interested in that PR but haven't had time to take a look at it in detail. Do you have some sort of ETA for when you might?