COMMON: make non-existence of gda_common library non-fatal

(cherry picked from master commit 6c3274d480bba145acec7db50a6923db112016a8)
MapBasedDictionary - to allow simple creation of dictionaries in Spring
Merge remote-tracking branch 'origin/1.3'
Merge branch 'master' of ssh://dascgitolite@dasc-git.diamond.ac.uk/gda/gda-common.git