nuageinit: Fix passwords

The hashed password usually contains a "$" sign, which, when used on a
shell, must be escaped. Also, the plain text password may contain
special characters that require escaping.

Add a quick fix by enclosing it in single quotes. Note that if the
plain text password contains a "'", it will still fail. This will be
properly fixed in later commits.

Some here documents require the document to be a string literal,
especially when passing invalid characters. Enclose it in single
quotes.

Signed-off-by: Jose Luis Duran <jlduran@gmail.com>