Build v0.1.4

Changes:
- added exceptions for invalid parameters for constructors of 'Reise'
- simplified toString() of 'Reise'
- implemented getReiseziele() of 'ReiseContainer'
- improved size() of 'ReiseContainer'
- implemented toString() of 'ReiseContainer'
- changed constructor of 'ReiseServer' to automatically start the server
in a new thread (not yet finished)
- removed some unnecessary code from bucheReise() of 'ReiseServer'
- included a complete junittest for 'Reise'

Notes:
- still no working build available
- need to revisit bucheReise() of 'ReiseServer'
- need to implement sorting in hinzufuegenTeilnehmer() of 'Reise'
- will add junittests for all classes

Signed-off-by: Dominik Beppler <dbeppler@web.de>