Save password generator settings

Remember the used values for the password generator and restore them the
next time the user opens the generation dialog.
Initialize variables to silence compiler warnings.
Print a cmake feature log.

This let's users know when the dependnecies for auto-type are missing.
Available only in cmake >= 2.8.3.

Closes #71
Improve error messages for reading and wriiting databases.

Closes #7
Simplify password classes
Merge branch 'password-generator'