Do not use QApp::arguments() to select antialiasing mode.

This selection typically interfers with an application's command line
arguments. Creator's qml2puppet needs to set this mode to avoid
getting subpixel antialiased text from DesignerSupport.

Change-Id: Iabf2bece211b897c58e2933d5502fdcf7c360c55
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@digia.com>
Fix assert when calculating the implicit width of truncated lines.

Guard against reading past the end of the final line.

Task-number: QTBUG-31471

Change-Id: I489f742936ee16f12ad9762b7c0891bfa9377e21
Reviewed-by: Martin Jones <martin.jones@jollamobile.com>