add entered/left signal to pages

 - Now it is possible to connect at a time were every ui thing
   is setuped. So changes from script side at the ui can be done then.

Change-Id: I479378e1f3d3f02eda47b7ee28ced8077feab277
Reviewed-by: Iikka Eklund <iikka.eklund@digia.com>
Reviewed-by: Karsten Heimrich <karsten.heimrich@digia.com>
add a change installer ui example

Change-Id: I11b201ae39da42685e6eb0faf102e8cbcf3b6e4c
Reviewed-by: Karsten Heimrich <karsten.heimrich@digia.com>
fix unknown component value in scripts while updating

 - the order of initializing the updatercomponents list was different
   then the packagemanagercomponents list
 - now every updatercomponents are inside the list before the scripts
   are called

Change-Id: I2cfa8edb48326071f6976aa9f772afc477088719
Reviewed-by: Iikka Eklund <iikka.eklund@digia.com>
Reviewed-by: Karsten Heimrich <karsten.heimrich@digia.com>
avoid wrong replacings in the load script code

Change-Id: Ia0d437fe1200ffa692e7b9a204622619934e92a5
Reviewed-by: Karsten Heimrich <karsten.heimrich@digia.com>