[VOL-2471] Update library to use package logger
This commit consists of the following:
1) Add a GetLogLevel() API to make it easier to use specific
logger. There is also the V() API that kind of do something
similar.
2) Add a common.go file to some heavily used packages in order
to dynamically set their log level and also to a set a specific
logger per package.
3) Use a per package logger for some of the heavily used packages
for improved performance.
Change-Id: If22a2c82d87d808f305677a2e793f8064f33291e
26 files changed