Remove the dedicated column for right aligning numbers.

[David Hampton]

Log Message:
-----------
Remove the dedicated column for right aligning numbers.  This is done
via a simpler method now.

Tags:
----
gnucash-gnome2-dev

Modified Files:
--------------
    gnucash/src/gnome-utils:
        gnc-tree-model-account.c
        gnc-tree-model-account.h
        gnc-tree-model-commodity.c
        gnc-tree-model-commodity.h
        gnc-tree-model-price.c
        gnc-tree-model-price.h