qv4isel_moth.cpp: Fix MSVC-warnings about operator unary minus applied to unsigned.

compiler\qv4isel_moth.cpp(1041) : warning C4146: unary minus operator applied to  unsigned type, result still unsigned
compiler\qv4isel_moth.cpp(1056) : warning C4146: unary minus operator applied to  unsigned type, result still unsigned
compiler\qv4isel_moth.cpp(1096) : warning C4146: unary minus operator applied to  unsigned type, result still unsigned

Change-Id: Idb4714a277486ff736f49c50c7e840fd62e2150f
Reviewed-by: Lars Knoll <lars.knoll@digia.com>
Fix context creation failure message.

Add missing newline, fix placeholders in translator's comment.

Change-Id: If80d237a97096a319a67da4c75c5e32c47576aee
Reviewed-by: Robert Loehning <robert.loehning@digia.com>