To do #1: Memory page allocation

[vercas]

I will be using the page map for info and O(1) deallocation of a single page (instant check).
A stack will be used for storing free and caching page indices. This allows O(1) allocation of a single page.

Reserved pages should stay forever reserved, so there is no point in storing them in a stack.
Used pages don't need specific storage. When used pages need to be used (e.g. reallocation to make room for consecutive pages), the map needs to be looped over anyway.

I do not believe I will need to allocate consecutive physical pages often, and I really do not like the implications of every algorithm that would allow quicker multi-page allocation.

The same "stack" will contain both free and caching pages, but the stack will have two "tops". The caching pages sit above the free ones.
E.g. when a free page is popped, the free top decrements, the top caching page is written in its place and the caching top decrements. Performance should be satisfactory.

[vercas]

Appears to be done.

[vercas]

Clearly this issue is not yet solved!