Fixed link to Qt Test tutorial and fixed naming (QTestLib -> Qt Test).
Fixed link to Qt Test tutorial and fixed naming (QTestLib -> Qt Test).

Change-Id: Ib776c70b2db2e5851d24c04e7906c90b1497f82b
Reviewed-by: Leena Miettinen <885fda02d52616fec24ed5fed9b3f0568fce3ead@digia.com>

kobolabs/qtdoc,kobolabs/qtdoc,kobolabs/qtdoc,kobolabs/qtdoc