Build v0.1.5

Changes:
- 'Reise' now completely working
- junittest for 'Reise' finished and working

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

Signed-off-by: Dominik Beppler <dbeppler@web.de>
Build v0.2

First Working Build, yay!

Changes:
- wrote test data into reisen.txt
- added more javadoc comments, full javadoc will be provided with v0.3
- added autoflush to all PrintWriters used
- corrected request send by buchen() in ReiseClient
- implemented getFreiePlaetze() and getReiseziele() in ReiseClient
- changed verbinden() to check for already existing connections and
always create a new Socket when reconnecting since you can not reconnect
a closed socket
- improved hinzufuegenTeilnehmer() in Reise and made it synchronized
- constructor of ReiseContainer now checks if reisen.txt exists before
trying to load it. whenever it does not exists it will be recreated
automatically in the default location
- implemented laden() and speichern() in ReiseContainer
- changed toString() in ReiseContainer to return the correct String
representation of the object
- added fully working junit test for Teilnehmer
- complete implementation of server-client communication in both classes

Notes:
- javadoc needs much more work

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