Use equally-sized buttons in wxMSW horizontal toolbars

Only use TBSTYLE_AUTOSIZE, adjusting each button to the size it really needs,
for the toolbars with wxTB_HORZ_LAYOUT style as they don't have any uniform
button size anyhow.

docs/changes.txt

@@ -108,6 +108,7 @@ wxMSW:
 - Fix MDI menu display after failure to create a child frame (troelsk).
 - Fix wxScreenDC::GetSize() with multiple monitors (iwbnwif).
 - Fix background colour returned by wxTextCtrl::GetStyle() (Andreas Falkenhahn).
+- Revert to using equally-sized buttons in wxToolBar by default.
 
 wxOSX:
 

src/msw/toolbar.cpp

@@ -1095,7 +1095,7 @@ bool wxToolBar::Realize()
                 // automatically according to the size of their bitmap and text
                 // label, if present. They look hideously ugly without autosizing
                 // when the labels have even slightly different lengths.
-                if ( !IsVertical() )
+                if ( HasFlag(wxTB_HORZ_LAYOUT) )
                 {
                     button.fsStyle |= TBSTYLE_AUTOSIZE;
                 }