allow true/false for onoff config setting

Changed the values recognized by the general config parser.
If value in config is a boolean it is recognized as boolean, not if it
is a string.

Fixes #718

fixed problems with spaced arrays

added failing test for array type

started to add some unit tests to config manager

Parsing the config file should be completely tested before we can rely
on it and safely extend it. This just adds the first very basic tests.