port common utilities to OSGi services

the different kind of common services that were available through a
singleton in the old design are now registered as OSGi services in the
common bundle activator.
This includes:
 - the template engine
 - the email client
 - the couchdb client
make OSGi utilities more monadic

an implicit rich service reference class adds the
map/flatMap/foreach/withFilter methods so that it can be used in
for-comprehensions
improve modular configuration

each bundle now loads the configuration from either of these locations:
 - the bundle specific configuration directory
 - the base configuration directory
 - the bundle classpath