[mythtv] More scheduling scheduler

[Max Barry]

Max Barry wrote:
> David Engel wrote:
>> Change the push_front on retrylist to push_back. That reverse
>> ordering possibly isn't needed any more. 
 >>
>>> More seriously, I was able to get MythTV to conflict a program solely
>>> because of softpad--which should never happen. See softpadtest2.txt for
>>> details. This required me to schedule 5 programs on 2 channels with 2
>>> tuners, a situation of unusually high load, but it's not unthinkable,
>>> either.
>>
>> I'm not terribly surprised. The backtracking done in the scheduler is
>> very limited. If soft padding nudges it down a different path, there
>> isn't always a way back.
> 
> Hard conflicts caused by soft padding are pretty bad. They violate the
> most essential rule of the function. Is this fixable? 

I manually changed push_front to push_back, had a play, and was unable 
to cause a conflict. So perhaps that's all we need.

If that change is actually going into svn, I'll test more thoroughly.

Max.