General - Optimize some if statements

[PabstMirror]

a tiny bit faster to remove the not
these are mostly in functions that may be called more frequently

[LinkIsGrim]

Code is fine, but I think this is less readable. Worth it?

[BrettMayson]

imo it is more readable, with maybe some exception, when it is as readable. The code is the same, it's still if else, it's just swapped order

[rautamiekka]

Way more readable cuz it ain't backwards.

[LinkIsGrim]

the people have spoken

[johnb432]

Code is fine, but I think this is less readable.

I feel the same way for most isNull/isNil checks, but it doesn't matter much.