buildmakejobs 0 by default to allow parallel builds

[Ryan Schmidt]

Why don't we set buildmakejobs to 0 by default in the macports.conf?  
Setting it to 0 makes MacPorts set the number of make jobs to the  
number of processors or processor cores. Currently, we default  
buildmakejobs to 1, meaning software is not built in parallel.

We already require individual ports to declare "use_parallel_build  
yes" in order to get parallel building. So any ports that say  
"use_parallel_build yes" have been specifically tested and found to  
work in a parallel build environment. So why don't we allow users to  
benefit from this out of the box? I would expect that many users  
don't even know they can speed up their builds by changing  
buildmakejobs.


On my system, I also set buildnicevalue to 1, instead of the current  
default of 0, so that other tasks on my computer are still snappy  
while MacPorts is building something. IMHO something nonzero would be  
a better default value for buildnicevalue.



Comments?