Add a ToDo file containing changes for v7 of OpenDoors. These are changes

which will break the ability to drop in an updated library and have the door
Just Work.

src/odoors/TODO-v7.txt

+Features/Changes which will break the API and so must go into v7
+----------------------------------------------------------------
+- Do not pack the od_control structure in memory.  This is plain silly.
+- Do not use the BOOL type in od_control or in any of the public functions.
+  Using it causes problems with stuff that defines a BOOL as a different
+  size.  For example, xpdev uses int as a BOOL whereas OpenDoors uses a char