[FaceRest] Move handler*User() to FaceRestUser.cc (issue #156)

In addition, PrivateContext & RestJob are moved to
FaceRestPrivate.cc to access to them from FaceRestUser.cc.
[FaceRest] Move handler*AccessInto() to FaceRestUser (issue #156)
[FaceRest] Move handler*UserRole to FaceRestUser.cc (issue #156)
[FaceRest] Move parseUserParameter() and parseUserRoleParameter() to FaceRestUser.cc (issue #156)
[FaceRest] Add some getter functions to avoid to refer PrivateContext directly

I'm planning to move back PrivateContext to FaceRest.
All privated operation should be done via RestJob.
[FaceRest] Move back PrivateContext to FaceRest.cc
[FaceRestPrivate] Remove needless include
[FaceRest] Remove needless trailing spaces
[FaceRest] Move implementations of RestJob to FaceRest.cc
[FaceRest] Rename some member function names of RestJob
[FaceRest] Move updateOrAddUser() to FaceRestUser.cc
[FaceRest] Remove needless trailing space
[FaceRest] Remove unused code
[server/src/Makefile.am] Remove nonexistent "FaceRestUser.h"
[FaceRest] Move getParam*() to FaceRestPrivate.h
[FaceRest] Fix indent
[FaceRest] Move handler*Server() to FaceRestServer.cc
[server] Rename FaceRest related source files

FaceRestServer ->
FaceRestHandlerServer

FaceRestUser ->
FaceRestHandlerUser
[FaceRest] Move handlerGetHostgroup() position
[FaceRest] Change some macro's position