Don't crash on Android

If the platform plugin does not support the features needed
for QQuickWidget, then don't try to use it. This is a minimal
change to stop applications from crashing: it does not give
the application a way to find out if QQuickWidget is supported,
since that would mean new API, which we can't do in a patch
release.

Task-number: QTBUG-38268
Change-Id: I975a03b105b1d5c21a1d8ae440a5802ce8c1967b
Reviewed-by: Laszlo Agocs <laszlo.agocs@digia.com>
Fix Number.toExponential with parameter

The fractionDigits parameter was unfortunately ignored, due to an accidental
double variable declaration, the latter in a narrower scope shadowing the
former in the correct scope.

Task-number: QTBUG-38577
Change-Id: I28f35466d2d744e84b86a3ca6b3371eb86869b55
Reviewed-by: Lars Knoll <lars.knoll@digia.com>
Fix failing assertion inside MSVC STL in debug builds

When using FunctionObject's call() method, we use std::copy to copy the
arguments over to the new call context. Unfortunately std::copy has an
assertion in there to check that we're not copying out of bounds.  What the STL
doesn't know is that the Value args[1] array is dynamically allocated and
easily expands beyond just one entry.

Fall back to copying by hand to work around this issue.

Task-number: QTBUG-38195
Change-Id: I6e254b1c893ccf5cad2358179cda1b07b00228e0
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>
Reviewed-by: Lars Knoll <lars.knoll@digia.com>