Before this fix suggestion links were built out of fully URI-encoded
book name and article path components despite the fact that this measure
was taken against only a few dangerous symbols such as '#', '?', '"' and
'\'. However, URI-encoding the slash symbols in the path has some
undesirable side-effects (see #958).
Henceforth only the problematic symbols are encoded in the article path
component. The book name is still fully URI-encoded since I don't see
any counter-arguments.