don't take the min size into account when setting the window size explicitly in wxGTK, just as wxMSW doesn't do it; mention this in the docs and added a unit test to enforce this

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@53741 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

tests/test_test_gui.dsp

@@ -265,6 +265,10 @@ SOURCE=.\misc\selstoretest.cpp
 # End Source File
 # Begin Source File
 
+SOURCE=.\window\setsize.cpp
+# End Source File
+# Begin Source File
+
 SOURCE=.\geometry\size.cpp
 # End Source File
 # Begin Source File