[Planner Dev] Patch for cost and slack calc

[Kurt Maute <kurt maute us>]

Hi All,

I submitted a patch today to:
1. Change summary cost calculation so it's the sum of the child tasks
costs

2. Changed slack calculation so it always uses the default calendar and
doesn't pay attention to what resources are assigned to the task
(before, it had been using the same function that calculates the task
durations, which take resources and their individual calendars into
account, which isn't right since slack is based on calendar time
regardless of what resource is assigned).

The result of these recent changes is that now if you assign resources
to summary tasks, its basically for information only - they're not taken
into account in any calculations.  Summary task calculations are a roll
up of the child task values.

Please feel free to compile from CVS and try it out!

-- 
Kurt Maute <kurt maute us>