Status output related to OBS configuration is prefixed with the string
"OBS" and added padding for enabled and disabled features. This padding
was not aligned between platforms.
By moving the padding and prefix decoration into its own function,
both elements are controlled in a single place. CMake scripts were
changed to use this new function `obs_status` instead of using CMake's
`message` function directly.
Add the include directories found by cmake to the jack plugin.
This allows for the plugin to compile when the jack headers were
found in a directory that is not normally in the search path of the
compiler (e.g. /usr/local/include)
