Clean up TODOs from live documentation

TODOs showing up in ours docs look messy and are of no value to the
reader.

Remove these and log bugs for them to be written later.

Change-Id: Ib9244960e3cedce28b198449898e46668435fce9
Partial-Bug: #1626455
Partial-Bug: #1507065
Partial-Bug: #1626456