Fix uninitialised variable read

Found by Dr. Memory, run by Lubomir:
Error #48: UNINITIALIZED READ: reading register al
 # 0 StarWidget::mouseReleaseEvent()                        [qt-ui/starwidget.cpp:29]

Signed-off-by: Thiago Macieira <thiago@macieira.org>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Fix memory leak of the MinMaxAvgWidgetPrivate

Found by Dr. Memory, run by Lubomir:
Error #63: LEAK 24 direct bytes 0x344f42e8-0x344f4300 + 0 indirect bytes
 # 0 replace_operator_new                             [d:\drmemory_package\common\alloc_replace.c:2421]
 # 1 MinMaxAvgWidget::MinMaxAvgWidget()               [qt-ui/simplewidgets.cpp:64]

Signed-off-by: Thiago Macieira <thiago@macieira.org>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Delete the graphics items for the ticks and labels in the ruler

Ruler::updateTicks() was creating them, but nothing deleted them.

Signed-off-by: Thiago Macieira <thiago@macieira.org>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Fix all leak-at-exit from singletons in Subsurface

Subsurface creates a lot of singleton instances on demand, but nothing
ever deleted them. Since they are singletons, these memory allocations
are technically not leaks. However, they clutter the output in valgrind
and other memory analysers, hiding the real issues.

The solution is to delete these items at exit. For the models and for
gettextFromC, the solution is to use a QScopedPointer, which will delete
its payload when it gets destroyed. For the dialogs and other widgets,
we can't do that: they need to be deleted before QApplication exits, so
we just set the parent in all of them to the main window.

Signed-off-by: Thiago Macieira <thiago@macieira.org>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
More translations updates

Again, the author credit to me is wrong. I only did some of the German
translations. Everything else has authorship tracked on Transifex.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>