[Service][Builtin] Introduce Appmanifest installer

[Service][Builtin] Introduce Appmanifest installer

This built-in service introduces to support W3C AppManifest
installation, which is written JSON manifest file.

The overall goal of this feature is that
 1) Convert JSON manifest to config.xml
    - download proper icon
 2) Archive .wgt and request to install .wgt
    - tizen.archive is newly necessary to load

To support installation of archived wgt file from this feature,
there are 2 consideration to be solved.
 a) there is no signature file
 b) at least, public level certification is necessary

Change-Id: Iaf09bdfb3e6c5d6e8471ef91ea13fda863641db0
Signed-off-by: DongHyun Song <dh81.song@samsung.com>