Fix TzdbDateTimeZoneSource documentation to be saner.
Fix TzdbDateTimeZoneSource documentation to be saner.

Fixes issue 208.

nodatime/nodatime,BenJenkinson/nodatime,BenJenkinson/nodatime,zaccharles/nodatime,zaccharles/nodatime,malcolmr/nodatime,nodatime/nodatime,zaccharles/nodatime,zaccharles/nodatime,jskeet/nodatime,jskeet/nodatime,zaccharles/nodatime,malcolmr/nodatime,zaccharles/nodatime,malcolmr/nodatime,malcolmr/nodatime