Add counter table (not yet fully editable, but on its way); add counter scopes

.gitignore

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

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

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

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

...de/community/OpenTools/Ordernumber/Model/Source/Reset.php

...de/community/OpenTools/Ordernumber/Model/Source/Scope.php

app/code/community/OpenTools/Ordernumber/etc/config.xml

app/code/community/OpenTools/Ordernumber/etc/system.xml

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

var/connect/OpenTools_Ordernumber.xml