doc: use reST note directive
The 'NOTE: bla bla' syntax was for asciidoc and is still present in a
couple of docstrings. The docstrings will be converted to reST format
when minirst knows how to handle it.
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
<head>
<link rel="icon" href="{staticurl}hgicon.png" type="image/png" />
<meta name="robots" content="index, nofollow"/>
<link rel="stylesheet" href="{staticurl}style-monoblue.css" type="text/css" />