Switch to tree_magic_mini fork

[mbrubeck]

This removes several old crates from the dependency graph.

[phiresky]

Do you have some more info about that fork?

[mbrubeck]

I created this fork based on the tree_magic master branch, with one commit reverted to fix compiler errors. I included my pull request to upgrade to nom 5.1, aahancoc/tree_magic#20.

I also included some optimizations and cleanups that I found while doing the nom 5 upgrade, and removed some optional code to simplify and shrink the library. From the README:

This is a fork of the tree_magic crate by Allison Hancock. It includes the following changes:

• Updated dependencies.
• Reduced copying and memory allocation, for a slight increase in speed and
  decrease in memory use.
• Reduced API surface. Some previously public APIs are now internal.
• Removed the optional cli feature and tmagic binary.

These changes were made both to make the library more efficient, and to simplify the effort to maintain and optimize of this fork. I would like to eventually merge these changes back to the original tree_magic crate, and/or restore some of the removed features if there is demand for that.

I've also offered to help maintain the original tree_magic at aahancoc/tree_magic#16.

[phiresky]

Sounds good