Doc: public test functions in function libraries

Task-number: QTBUG-29168

Change-Id: Ife486d65778ee2ac2d6e1e55f26942bda0bbdbb0
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@digia.com>
Cut away 2/3 of the startup time on Linux

Optimize the parser of the X11 compose tables. Parsing these was
responsible for over 90% of the startup time in Qt 5.1.

Change-Id: Ifddc3f30828791e51a755f92791c26ffe43a9cd3
Reviewed-by: Konstantin Ritt <ritt.ks@gmail.com>
Reviewed-by: Lars Knoll <lars.knoll@digia.com>