Beam collision push

[Mike Solomon]

Hey all,

Han Wen - I saw that you pushed your beam collision work to master branch.

I truly feel that this is premature and I urge you to undo it.  The reason I 
have not pushed my patch yet is because I think more people need to chime in.  
This type of collision avoidance is very important to my current work as a 
composer, and the version that you pushed will not be able to correctly account 
for several types of collisions, as you saw in the files that I sent out to the 
list (unless you have modified it in a way of which I'm not aware), not least 
of which are the type that Neil sent out to the list and that my patch 
currently deals with.

Collision avoidance is a brute-force manipulation of the beam that is 
difficulty to justify in quanting, which should deal with a discrete range of 
limited possibilities.  It forces one into a cycle where one has to guess the 
appropriate region size to catch large collisions and recompile to see if one 
was right.  In doing so, the region size increase invariably increases the time 
of compilation.  It also does not allow for fine tuning of beam collisions on a 
grob-by-grob basis, which you see in action in the response I sent out to Neil.

Please, again, I urge you to undo this before people start building on it.  I 
do not believe that it is a tractable long-term solution, and I feel that 
pushing this early kills any dialogue on a better way of going about this.

~Mike