Migrate all non-trivial responses out of serve()
Migrate all non-trivial responses out of serve()

The case statements in serve() were really unwieldy.  This migrates most
of the non-trivial case statements out into separate functions of the
same name.  Subsequent changes will handle Read and cleaning up the
casing of the function names.

asjoyner/fuse_gdrive,devilmonastery/fuse_gdrive,hatchling/fuse_gdrive,asjoyner/fuse_gdrive,hatchling/fuse_gdrive,devilmonastery/fuse_gdrive