This patch updates the docstrings in tools/ (mostly in lvmstrap, which
is very very old code-base) and then enabled the tools in this directory
for 'make apidoc' too.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: René Nussbaumer <rn@google.com>

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Guido Trotter <ultrotter@google.com>

epydoc seems to be mightily confused by decorators and how they change
functions (it starts mixing the parameters of the decorated function
into the decorator itself); so we want it to parse only and not look at
the objects themselves.

Reviewed-by: ultrotter

Currently the temporary directory used for modules is under the current
directory; this patch changes it so a temp directory is used; so we
could build the apidocs with a R/O filesystem.

Reviewed-by: ultrotter

Reviewed-by: imsnah

The patch adds the apidoc target and the epydoc config file for it. Note
that this is for epydoc 3.0 and that it will put the docs into
./doc/api/.

The patch also adds a new .gitignore rule for the auto-generated rapi
fragment.

Reviewed-by: imsnah