Proto commits in magefree/mage

These 4 commits are when the Protocol Buffers files have changed:

Commit:b215e9c
Author:Neil Gentleman
Committer:Neil Gentleman

specify proto2 syntax to prevent compiler warning

The documentation is generated from this commit.

Commit:972d59a
Author:Quercitron

Add user rating using Glicko rating system (#1498)

Commit:46e560b
Author:Me Car

Removed unuseful proto fields. Added a better pom.xml documentation. Removed an unuseful logging.

Commit:550648c
Author:Me Car

Record game histories. Compute user stats and show them in the user panel.