Splitting in two installers: wgt and tpk

Change-Id: I05a5f23ef1f1ee36988e5576f71018af6d169518
Signed-off-by: José Bollo <jose.bollo@open.eurogiciel.org>
wgt: checking existing config.xml

Change-Id: I5a6ae4b49f9e4545c8ad45bec0294a0bab7706af
Signed-off-by: José Bollo <jose.bollo@open.eurogiciel.org>