Fix possible memory leak in wxICOHandler loading code.

Use wxScopedArray<> instead of a raw pointer to ensure that the memory is
always freed, even in case of error return.

See #15918.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_3_0_BRANCH@76124 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Allow loading icons of width 256 from ICO files.

Account for the tweak of ICO file format which uses 0 if the width is 256.

See #15918.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_3_0_BRANCH@76125 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Handle verbosity correctly in wxICOHandler loading code.

Pass on the "verbose" argument to LoadDib() function instead of always being
verbose in it.

Also remove the unused IsBmp variable.

See #15918.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_3_0_BRANCH@76126 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Add support for loading icons in PNG format to wxImage.

ICO files can contain data in PNG, as well as BMP, format in recent (i.e. from
this millennium) versions of Windows, so check for this case in wxICOHandler
and load such data using wxPNGHandler.

See #15918.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_3_0_BRANCH@76127 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775