Add support for getting process memory and cpu usage information

[RMacfarlane]

• Add option to get memory for each process Add option to collect memory information from processes #11
• Add option to get CPU usage for each process Add option to collect cpu usage from processes #13
• Add option to get command line arguments for each process Add flag for getting command line arguments of processes #17

[weinand]

@RMacfarlane @Tyriar I would like to use these features but the npm module is not yet available, correct?
It would be great if you could publish this as soon as possible (so that I can use this in the March release of node-debug).

[Tyriar]

@weinand master should be on the new v0.2.0 👍