put filesystem utility functions in base (see utils.hpp)
more verbose output
Add support for "nomerge" merge option. Allow no matches in dataset.filename-pattern. Check for duplicate dataset names.
move glob function to base
make progress printing in ra/ra more better in case of errors
Support variable substituion in config files; support using output datasets from others as input datasets

Also add some flags for boost libraries to Makefile.rules
add support for shorter "HistFiller" configuration by supporting "_cfg" and "_dirs" statements
configuring many plots at once
cleanup: remove plot binaries from plot dir. They should go to individual analyses subdirs.
re-factored code to use process_type, selection_type and hname_type to identify things everywhere for more clarity

switched to string istead of ra::identifier for the various new *_types introduced, although
switching back should not be too hard.