o.c.archive.reader.rdb: Add preference for fetch_size

Original hard-coded value could result in out-of-memory error
Merge pull request #408 from ControlSystemStudio/bug407

o.c.archive.reader.rdb: Add preference for fetch_size
o.c.opibuilder: Update online help example for `ColorFontUtil`
Merge pull request #409 from ControlSystemStudio/bug406

o.c.opibuilder: Update online help example for `ColorFontUtil`: fixes #406
Merge remote-tracking branch 'origin/master' into sns