wave: make python wave library optional

The wave module is one of the rarely used modules. And we don't want too
many Python module library included at captcp start. Thus we make/treat
the python-wave library optional.

Note: python-wave is included in the Standard Python library. Python
wave is no third party module!

Signed-off-by: Hagen Paul Pfeifer <hagen@jauu.net>
SequenceContainer: make numpy library optional

Signed-off-by: Hagen Paul Pfeifer <hagen@jauu.net>
core: move python-cairo to suggested package list

Until now python-cairo was noted as a optional package. To generate
sequence graphs the cairo library is required. And sequence graphs are
a more important module.

Signed-off-by: Hagen Paul Pfeifer <hagen@jauu.net>
core: increase version number

Signed-off-by: Hagen Paul Pfeifer <hagen@jauu.net>