* ControlAdjuster.cc: New file, helper to move elements of a dialog
along when the it's resized.
* ControlAdjuster.h: Ditto.
* Makefile.am: Add new source files.
* proppage.cc (PropertyPage::DialogProc): Adjust some common
controls (Cygwin icon top right, separator below) when a page is
resized.
(PropertyPage::PropertyPage): Dito.
* propsheet.cc (IsDialog): New. Test whether a window is a dialog.
Used internally by resize logic.
(EnumPages): New. Used internally by resize logic: resizes the
property sheet's individual pages.
(PropSheetWndProc): New. Hook for the propery sheet window proc.
(PropSheetProc): More style tweaks, add maximize box and thick border
as well. Hook into the property sheet's window proc.
(PropSheet::AdjustPageSize): New. Adjust the metrics of a single page
to fit nicely into the property sheet. Part of resize logic.
* res.rc (All dialogs): The top-right Cygwin icon and top separator
now have IDs distinct from IDC_STATIC, so their metrics can be
adjusted upon a resize. Also, all those Cygwin icons are at the exact
same spot now.
* choose.cc (ChooserPage::ChooserPage): Now the controls on the
chooser page move/size when the page size is changed.
* choose.h: Dito.