add cli switch to enable verbose logging

this changes the previously verbose log messages to not be displayed by
default, they can be enabled by starting the pzh with "--debug". also
introduces info log messages to indicate successful start up.

Jira-issue: WP-1286
Merge pull request #47 from aldafu/WP-1286-make-verbose-logging-optional

add cli switch to enable verbose logging
Merge remote-tracking branch 'upstream/master'