make: build object classes in their sub-directories

Signed-off-by: Noah Watkins <noahwatkins@gmail.com>
hadoop: start deprecation by removing from build

Signed-off-by: Noah Watkins <noahwatkins@gmail.com>
make: build libcephfs.la in subdir

Signed-off-by: Noah Watkins <noahwatkins@gmail.com>
make: build librbd in its subdir

Signed-off-by: Noah Watkins <noahwatkins@gmail.com>
make: build libcephfs_java in subdir

Signed-off-by: Noah Watkins <noahwatkins@gmail.com>
make: build libcrush convenience library

Linked into libcommon as a dependency. Reduces cross-directory
compiling.

Signed-off-by: Noah Watkins <noahwatkins@gmail.com>
make: build json_spirit convenience library

Signed-off-by: Noah Watkins <noahwatkins@gmail.com>