[fpc-pascal] fpdoc enhancements

[Michael Van Canneyt]

Hi,

At the request of some people on the lists, 
I added the following enhancement to fpdoc:

If a method has no documentation node, the documentation will be searched
in the ancestor tree. The first parent with a documented node will be used,
and will be referred to from all overview pages.

This actually already existed. However, since makeskel emits nodes for
all methods, it probably was never noticed. 

So I have enhanced it with the following:

You can add a link tag:

<element name="tchild.method" link="tparent.method"/>

This will look for the documentation in tparent.method. 
This can be used to speed up the process, and can also be used
to skip certain parents.

Note that this mechanism only works with methods of classes.

Additionally, I have enhanced makeskel, so it now has an option 
--disable-override
It will then no longer emit nodes for methods which have the 'override' directive.

Being busy with it anyway, I also added 2 more things:

--emit-declaration
which will put the declaration of an identifier in front of an element
node, in a comment node.

--sort-nodes
Writes the nodes sorted alphabetically - within the limit of a unit.
(obviously TChild.Method comes before TParent.Assign and so on)
 
Finally, the makeskel code has been cleaned up in general as well.

I didn't merge this to fixes.

Michael.