Support wildcards for filtering torrent list and torrent content

[vlakoff]

Supersedes #4164.

Uses the WildcardUnix mode.

[sledgehammer999]

Fix this error:

gui/torrentcontentfiltermodel.cpp:41:41: error: ‘setPatternSyntax’ was not declared in this scope

(and similar ones on the other variables)

[vlakoff]

@sledgehammer999 It should be fixed now. (some confusion between QRegExp and QSortFilterProxyModel, I apologize)

However, I had to change to Wildcard mode. If you would prefer WildcardUnix mode, I have another branch ready as well.

[sledgehammer999]

IMO, WildcardUnix is a better mode. So rename you other branch to this one, and then force push onto this one. This PR will autoupdate.

[vlakoff]

I prefer WildcardUnix too. This branch has been updated and should be ready to go.

[vlakoff]

Just to point out there shouldn't be a loss in performances, as the FixedString mode also works using a regex that is escaped. So the only added calculations are the QRegExp instanciations instead of reusing instance.

[sledgehammer999]

Thanks.

[vlakoff]

Just referencing issue #4065 which this PR solved.

[vlakoff]

I added a comment on a related PR, about updating this code to QRegularExpression: #9255 (comment).