Disabled Android Storate and Android Dropbox storage

- Because of file permission problems ownKeepass cannot write database files on Android storage. It is in principle possible to chmod the file permissions but this is totally out of scope for the average user. So for now I removed the options to store and load the database from those locations.
Added version handling

- Version is now set in yaml file and propagated to spec and .pro file. Throug a define it is pasted to c++ and from there to QML. Voila :)
- This closes #24.