Merge 2.4 source

Merge 2.4 source

update doxygen

added:
package_manager_drm_generate_license_request
package_manager_drm_register_license
package_manager_drm_decrypt_package
package_size_info_get_data_size
package_size_info_get_cache_size
package_size_info_get_app_size
package_size_info_get_external_data_size
package_size_info_get_external_cache_size
package_size_info_get_external_app_size

*note: drm apis should be implemented later

Change-Id: I9f9794157124d1f134310d922f6a79b1d6c0ecc8
Signed-off-by: Sangyoon Jang <s89.jang@samsung.com>