#88 make strings for Staff and Members translatable

[Wolfram Sang]

For my use case, I want to have error messages related to Staff and Members also in my langauage. So, here is a patch against 0.7.2. which prepares those two classes for internationalization. It can also be applied to the German version 0.7.2.1g if you allow patch to reduce the fuzz a little. In a seperate patch, there is the German translation for 0.7.2.1g.

[Wolfram Sang]

The German translation.

[Wolfram Sang]

Both patches included in the German version 0.7.2.2g to be downloaded at https://openbiblio.de/.

[Raluca Ivan]

The Roumanian translation , please!