Refactor node pool a bit
Doc
Enable STDERR line buffering
Make DSN DB removal exception-safe
Refactorings
-W/HLint, enable -W in fast builds
Add non-linking build type 'nolink'
Code style, indentation
Change config file
Put DB functions into separate utilities module
Fix wrong client cleanup
Move server/client DB functions to DB module
Merge branch 'more_dsn_than_usn_hotfix' into develop

This partially fixes #20 (more DSN than USN).

Conflicts:
	src/Client.hs
Refactorings
Merge branch 'develop'