[SPARK-12248][CORE] Adds limits per cpu for mesos coarse mode

[drcrallen]

• Add spark.cores.mb.min for minimum memory per core
• Add spark.cores.mb.max for max memory per core

[AmplabJenkins]

Can one of the admins verify this patch?

[drcrallen]

Doesn't affect heap memory properly, closing until fixed

[drcrallen]

local fork of spark at https://github.com/metamx/spark/tree/v1.5.2-mmx is using this successfully, but since #10993 will probably be the way to go forward, I'm not going to re-raise this PR unless requested.

[PedroAlvarado]

@drcrallen Did #4027 covered the memory constraints you were adding as part of this issue? I can't find another open or closed issue that addresses the issue raised here.

[drcrallen]

@PedroAlvarado I just looked at master and 2.0 and the limit of one task per slave seems to have been removed. I do not think this is valid anymore. Closing out ticket.