New slots

In 1.0, the main_template contains six additional slots which will be created
at product installation and can be "filled" on the properties tab of the
respective Plone Site:

• slot_1   -  top left corner
• slot_2  -   top right corner  
• slot_3   -    between tabs and page title
• content_top  -   at title, document gets pushed down 
  (can substitute portlet instead of title by putting # in document title) 
• content_bottom  -   document foot, in line with main document
• slot_4   -  below content_bottom, left aligned in line with navigation bar.

At installation, slot_1 and slot_2 are automatically filled with static_portlet_1
and static_portlet_2 respectively.

The corresponding properties (named slot_1_slots, slot_2_slots etc.) are created for public_home if such a folder exists at installation time, and for the root otherwise.

left_slots and right_slots will also be added to public_home with the same settings as on the root. The 'add-in' pages created in 1.1 automatically fit to predetermined positions which take the place of these slots, thereby rendering the need for them obsolete.