Fix change-of-sign warning

qgstappsrc.cpp(54): warning #68: integer conversion resulted in a change of sign

Change-Id: I0bf8c93cb5e27114a8857dc650ac506152607491
Reviewed-by: Yoann Lopes <yoann.lopes@digia.com>
Add meta-data accessors to the QML Camera type.

Add write accessors to the properties of QDeclarativeMediaMetaData as
well as additional properties for previously unmapped image keys and
add a metaData property exposing this to QDeclarativeCamera.

[ChangeLog] New metaData property for the QML Camera type.

Change-Id: I4456b7b6120842f7ad9a1b175e42b9fb332adf13
Reviewed-by: Yoann Lopes <yoann.lopes@digia.com>