peer: Rename MRU to LRU.

[randomshinichi]

Fixes #967

[davecgh]

Thanks for the PR.

I haven't really reviewed this in depth yet, but a couple of things right away:

• It's failing the unit tests. That will need to be resolved.
• Also, per the referenced issue, it should be lruInventoryCache and lruNonceCache as opposed to lruInventoryMap and lruNonceMap, respectively.

[randomshinichi]

Made the changes. I even changed map -> cache in the comments, although I'm not sure that's entirely a good idea. A cache sounds too general - a map makes me think of a hash map, which would be one concrete way to implement a cache. Have a look and tell me what you think.

[davecgh]

Nice. Thanks for the updates. The code looks good.

The last bits will be a few things related to the commits and then we can get this merged:

• Please make the commits match the Model Git Commit Messages in the code contribution guidelines. Most notably to make sure each one has a prefix which describes the package it touches (they're all peer here).
• Please do not include issue numbers in commits because they end up referring to the wrong issues when they get merged into other repos during syncs. Instead, issue number references should be limited to the git PR descriptions.
• Squash the comment update commits into their respective rename commit. Ideally this PR would only be 2 commits (One for the MruInventoryMap to LruInventoryCache rename and updates, and a second one for the MruNonceMap to LruNonceCache rename and updates).

[davecgh]

Once the review comments are addresses we can get this merged. Feel free to pop into the dev channel on irc/slack/discord if you want to discuss.

[randomshinichi]

I tidied up the commits. Splitting them up per component would've taken too long, though. I think doing it this way makes logical sense too.

I might use this model git commit format for my code too.

[davecgh]

Thanks for the updates. Looks good.