Fix eslint issues

[germanferrero]

This PR:

• Removes eslint rules from "synacor" which provided many "formatting rules".
• Keeps only those "code quality" rules. (non used vars, useEffect dependencies, etc).
• Fixes all left eslint issues (except those of lime-plugin-fbw, to avoid merge conflicts with upcoming PR).
• Add a pre-commit hook to lint staged files.

@selankon, could you give it a try?