Remove the skins folder and script

[keul]

Now that issue https://dev.plone.org/ticket/11317 has been closed, we don't need a custom folder_position script.

See also plone/Products.CMFPlone@a734a1c

[mauritsvanrees]

We don't need the custom script if the end user has Plone 4.3. For older Plones it is still needed.

Also, I have just added a branch (renewed from an older branch that I have now removed) where I add some more small changes to the folder_position script. See pull request #3.
I have added those changes in CMFPlone too just now, but they have of course not been released yet:
plone/Products.CMFPlone@ee99d89

So I would say: we still need the skins folder and script.

[keul]

Ok, so let's keep this open for a while.
When a new Plone version (4.3.4?) will be released we can probably drop the skin folder and release a new (2.0) version that drop compatibility with older Plone.