CAF::Path documentation: methods should be in alphabetical order or grouped in sections

[jouvin]

As of 16.12, it is difficult to get an idea of what CAF::Path does based on its documentation (and it does many things!). This is due to the fact that the methods appear in fact by logical groups but that these groups are not reflected in the doc structure. May be an additional level of headings, index in the table of contents could help.