Launchpad automatic translations update.
Translation of descriptions to pt_BR for new landscapes
StelPainter::drawText does not change the opengl blending state

I added a RAII class that save the opengl blending state and automatically
restore it in its destructor.  So far I use it only in the drawText method, to
fix a bug in the compass mark plugin.
minor fix in compass marks plugin
merge from parent
change compass marks plugin to use StelAction instead of QAction
remove last QAction ref from compass mark plugin

Since StelAction are automatically updated when the property they are linked to
change, this line was unnecessary.
updated CMakeLists.txt
fixed text for action for Compass Marks plugin
restore cmake policy for Windows
added checks of file formats for plugins
fixed building on Windows
updated InnoSetup script for Windows
oops... fixed missed Network module for shared stelMain library
updated generator of InnoSetup script
allow to connect StelAction to slot of the form `func(bool)`

It is better to instead connect the action to a property, so that the action
can also read the initial value and react to external changes.  I just add this
because it will make it easier to modify the ocular plugin to use StelAction.

I also added an empty StelAction constructor and a setCheckable method, also
just there to simplify the port of the ocular plugin.  Eventually we could
remove those.
add a StelButton constructor that accept a StelAction instead of an QAction

I am not quite sure this is legal C++, but I am going to clean all the
StelButton constructors as soon as all the QAction are removed from the code
anyway.
replace all QAction to StelAction in ocular plugin

This might break some things.
Launchpad automatic translations update.
remove last QAction reference from ocular plugin