Move essential dynamics / flooding code to separate directory

Part of #1415 Get rid of legacyheaders.

Additional changes:
- provided doxygen-style documentation for functions in edsam.h
  (partly copied over from edsam.c and removed there to avoid
  duplication)
- uncrustified edsam.c and edsam.h

Change-Id: If4af498470c5200d50ac1d1b5537917c873380b5