Include the Reports menu in the main user interface.

[David Hampton]

Log Message:
-----------
Include the Reports menu in the main user interface.  Extracted common
code into utility functions.  New function for adding hand crafted
actions to the user interface.  Don't allow the initial page to be
closed or moved.  Rename a menu entry.  Remove the dispose function.
Add doxygen comments.

Tags:
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gnucash-gnome2-dev

Modified Files:
--------------
    gnucash/src/gnome:
        gnc-main-window.c
        gnc-main-window.h
    gnucash/src/gnome/ui:
        gnc-main-window-ui.xml