Rework of #39 (#40)

* Rework of #39 patch from @arykov (thanks)

* styled resize corner

* fixed squashing of resizaable window on moving

* keep window size and opsition after full screen

* not necessary

* attempt to fix desktop overflow

* improved

* ios fixes

* refactoring

web/kvm/windows.pug

@@ -1,10 +1,3 @@
-mixin window(id, title, with_header_id=false, close_confirm_msg="")
-	div(id=id class="window" data-close-confirm=close_confirm_msg)
-		div(id=(with_header_id ? `${id}-header` : "") class="window-header")
-			div(class="window-grab") #{title}
-			button(class="window-button-close") ×
-		block
-
 include window-stream.pug
 include window-keyboard.pug
 include window-about.pug