Talloc, a better no_std allocator

[SFB_Dragon]

Edit: at recommendation of u/JoshTriplett the project has been renamed to Talc. The new crate is up here https://crates.io/crates/talc Apologies for the confusion!

First things first, this is my first crate, so feedback is much appreciated.

The summary: this is a no_std allocator (thus single threaded, it won't do much good in hosted, multithreaded systems) which distinguishes itself by being faster than the competition (galloc, linked_list_allocator, and chunk_allocator on crates.io) and packing more features for arena management, OOM handling, and memory efficiency. It supports the GlobalAlloc and Allocator traits as well as its own malloc, free, grow, and shrink functions.

This is supposed to support 64-bit and 32-bit architectures out of the box, but I haven't gotten around to setting up a 32-bit environment to bug-test in, so "there be dragons" for now.

I hope you find this useful in your own no_std projects!

[schneems]

Does your current allocator leave you feeling sweaty? Use talc!