FIX: build system extension loading
FIX: Service provider app terminates after start
Do not background Service provider app

We cannot auto-terminate because Platypus currently breaks
auto-termination of drop target apps, so we should at least allow the
user to interact with the app.
Skeleton Readme

Not very useful unless you are beta testing the package.
Build system: factor out Info.plist manipulation

Allows for more flexible, if slightly more verbose, Info.plist
mainpulation.
Refine Info.plist post-processing

Use InfoPList class; refine NSService keys for Service provider app and
remove document handlers.
Build system: housekeeping
MultiMarkdown type handling for Service provider app

Import all relevant UTIs for MultiMarkdown compatible processing
and restrict file handling of both the service and drop target to these.
README improvements
Version bump to 2.0.0b3