Add --verbose option to reduce help text in callgraph and flatprofile

Technically it is possible to pass -v multiple times to increase the
verbosity level, we don't make use of it as of now.

Signed-off-by: Stefan Beller <stefanbeller@googlemail.com>
Implement suggestions on verbosity parameter.

Signed-off-by: Stefan Beller <stefanbeller@googlemail.com>
Merge pull request #6 from stefanbeller/verbose

Add --verbose option to reduce help text in callgraph and flatprofile