E&S CVS Commit: Trellis - Move "todo/future" functionality into a TodoValue class that

[pje at eby-sarna.com]

Author: pje
Date: Fri Dec 28 12:15:22 2007
New Revision: 2448

URL: http://svn.eby-sarna.com?rev=2448&view=rev
Log:
Move "todo/future" functionality into a TodoValue class that
tracks the earliest savepoint at which the todo was accessed,
so that data structures will be able to rollback to that
point whenever any rule that modifies the todo is rolled back.
This will make it easier to create data structures without
writing tons of ``on_undo`` calls.

Modified:
    Trellis/Internals.txt
    Trellis/peak/events/trellis.py