for bugs 8033, 8065, 8535, 8582

This particular changeset contains style changes per code review suggestions 
and does not contain bug fixes in of itself.

ha_federated.h:
  standardised code style to conform to internals.texi
ha_federated.cc:
  more code standardisation to conform to internals.texi.
  - casts
  - declarations
  - comments
  - 80 char width
  also, append using string1.append(string2) and not 
  string1.append(string2.c_ptr_quick())