Now if there is no "rootpath" specified, it's not even listed by
FilesPageHandler and ListAjaxHandler. And, of course, not available to
use anywhere else.
Paths containing '../' are forbidden to use in Files Manager. There is
also a special inner black list of paths which are not used and a check
that specified path is under "savepath" or "rootpath" (from "cloud"
domain).
Its handlers are now more compact. This commit moves Handler classes in
handlers\ directory.
ResourceHandler ignores "hidden" files in the archive, and these are
used as markup templates in IndexPageHandler and FilesPageHandler.
