Rename Netsteria to MettaNode.
Enable clean build on mac, no warnings.
Remove stale Opus documentation comments.
Fix errors found via -Wdocumentation.
Compile opus on linux.
Build file cleanup.
Rename README file.
Remove opus, will be pulled from a repo.
Add 'ui/3rdparty/opus-1.0.1/' from commit '5ac07d3f2c62baa8b1c860fa066046fe8183d862'

git-subtree-dir: ui/3rdparty/opus-1.0.1
git-subtree-mainline: 9e006380b1cc2ec6e86c19bdca0054a14e762a8f
git-subtree-split: 5ac07d3f2c62baa8b1c860fa066046fe8183d862