Power of Two cached arrays only

[thygrrr]

Changed ArrayPool so it will only work with Power of Two arrays. There are various questions that remain, including whether the mod as it is will work with this. Feeding the arrays given to compress into the cache, however, constitutes a memory leak; and if anyone who called compress reuses this array, this causes undefined corruption.

Fixes:

• correct powers of two used (was a +1 error, and very bad effects for negative values)
• tests adapted
• new tests to prove we are actually recycling arrays

Last question:

• do you have a git content filter? somehow, a large portion of the lines in each file are considered changed. this could be line endings or tabs or whatever. It is possible to hide whitespace in diffs, though... https://github.com/LunaMultiplayer/CachedQuickLz/pull/3/files?utf8=%E2%9C%93&diff=split&w=1

[thygrrr]

I tried to write a adapted version of this test, but it wouldn't work.

[thygrrr]

I don't think this should be merged. :( 👎 At least not before I find out why compress suddenly needs memory.