Rationale: The concept of a "Qt Dir" is dead ever since Qt can be
installed. Specifying the qmake location otoh makes it possible to
unambigously detect all parts of a Qt installation.
- Give the controls a tooltip listing file details (date)
- Make building a QtConcurrent task
- Make log window scroll to bottom and pop up on error
- Make the build code pass on error messages about copying the
source files to the log file
- Clean up the building code string-wise, use QLatin1String and
translate messages, cache the icons. Use a QSharedPointer for
the QtVersions in the settings page since they are passed to
the BuildTask, which may outlive the dialog.
- Give the controls a tooltip listing file details (date)
- Make building a QtConcurrent task
- Make log window scroll to bottom and pop up on error
- Make the build code pass on error messages about copying the
source files to the log file
- Clean up the building code string-wise, use QLatin1String and
translate messages, cache the icons
- clear up some Q_OS_LINUX vs. Q_OS_UNIX
- clear up Q_WS_* vs. Q_OS_* (relatively theoretical exercise)
- use proper #if-#else cascades instead of free-standing #ifs
