Display enhancements for device_query.py

[lukeyeager]

Makes device_query.py more useful. Previously, the output was 159 lines long (on my machine with 3 GPUs). Output is now 42 lines, with a --verbose option that allows you to see all the information if you still really need it.

$ ./device_query.py 
Device #0:
>>> CUDA attributes:
  name                         GeForce GTX TITAN Z
  totalGlobalMem               6432907264
  clockRate                    875500
  major                        3
  minor                        5
>>> NVML attributes:
  Total memory                 6134 MB
  Used memory                  771 MB
  Memory utilization           2%
  GPU utilization              9%
  Temperature                  45 C

Device #1:
>>> CUDA attributes:
  name                         GeForce GTX TITAN Z
  totalGlobalMem               6442254336
  clockRate                    875500
  major                        3
  minor                        5
>>> NVML attributes:
  Total memory                 6143 MB
  Used memory                  15 MB
  Memory utilization           0%
  GPU utilization              0%
  Temperature                  39 C

Device #2:
>>> CUDA attributes:
  name                         Tesla K40c
  totalGlobalMem               12079136768
  clockRate                    745000
  major                        3
  minor                        5
>>> NVML attributes:
  Total memory                 11519 MB
  Used memory                  23 MB
  Memory utilization           0%
  GPU utilization              0%
  Temperature                  31 C