LMS-445 introducing IMessageProvider and a Dictionary based implementation

openbis/source/java/ch/systemsx/cisd/openbis/OpenBIS.gwt.xml

...openbis/generic/client/web/client/application/Client.java

...lient/application/util/DictonaryBasedMessageProvider.java

.../client/web/client/application/util/IMessageProvider.java

...d/openbis/generic/client/web/public/generic-dictionary.js

...java/ch/systemsx/cisd/openbis/public/common-dictionary.js

...is/source/java/ch/systemsx/cisd/openbis/public/index.html