Change bootstrap server DB from List to Set
Read bootstrap server port from config
Individualize config parsers for the different services
Rename Config -> NodeConfig
Remove over-generalized MonadIO types
-W/HLint
Refactor arg parsers
Hide rare option fields from simple usage help
Fix swapped min/max neighbours defaults
Rewrite config+arg parsers to use modifier functions

(Warning: current implementation fugly. This is what Lens was invented
for.

The reason for the rewrite is to have a modification interface many
different config sources can hook into, such as config files and arg
parsers.

This commit breaks the build, as the other modules have not been
modified to accomodate the changes.
Adapt all files to the changes of the previous commit
Merge branch 'master' into develop
Refactor the ugly parts of options modifiers
Move configuration stuff to subfolder
Internal renames
Add config file handling skeleton
Add default config files
Merge with cmd arg parsing
Bring main functions up to date
Fix default config file