Fix some remaining warnings/bugs/translations

app/code/community/OpenTools/Ordernumber/Block/Counters.php

...de/community/OpenTools/Ordernumber/Block/Replacements.php

app/code/community/OpenTools/Ordernumber/Helper/Data.php

...ommunity/OpenTools/Ordernumber/Model/Backend/Counters.php

app/code/community/OpenTools/Ordernumber/Model/Observer.php

...ode/community/OpenTools/Ordernumber/Model/Ordernumber.php

...nity/OpenTools/Ordernumber/Model/Resource/Ordernumber.php

...rnumber/sql/opentools_ordernumber_setup/install-0.1.0.php

app/locale/de_DE/OpenTools_Ordernumber.csv

app/locale/en_US/OpenTools_Ordernumber.csv

var/connect/OpenTools_Ordernumber.xml