remove invalid email address from AUTHORS
better detection of whether we are linking to a shared/static QT build
add some names missing in AUTHORS
implement a --license command line option

This shows the complete list of authors and the full license text,
which are included in the compiled binary via QT resources.
update to the wk_4.8.6 branch based upon QT 4.8.6
remove reference to wk_4.8 branch
fix compilation failure with QT5/Windows
use Q_OS_xxx macros instead of Q_WS_xxx as per QT5 migration guide
fix compilation failure with QT4/Windows for a shared build
add missing entries to the DLL export list

The additional functions were introduced in 51036e686401251dbf550b3f884fb2f02d84c8d1
support "-debug" and "-clean" flags for all targets in build script
update URLs in the internal documentation
add missing name to AUTHORS