Don't use DDEExec registry key in wxMSW wxExecute() if it's empty.

Some file types have DDEExec subkey in the registry but no value for it, don't
use DDE for launching the files of these types in this case as this only
results in errors.

Closes #15388.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@74636 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Don't document wxSortedArrayString as deriving from wxArrayString.

This is no longer the case since quite some time.

Closes #15374.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@74637 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Update Travis configuration to run tests and build more configurations.

Install libcppunit-dev in order to be able to run the unit tests (at least the
non-GUI ones for now).

Also build in several configurations: shared/static, multilib/monolithic and
also STL. This should help to find problems appearing only in some specific
build variants.

Closes #15369.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@74638 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Add wxFileName::SetPermissions().

This is a simple wrapper for the POSIX chmod().

Closes #12951.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@74639 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Define __VISUALC__ for ICC under Windows again.

During the refactoring of r74496, the logic of the check for Intel compiler
was slightly altered resulting in not defining __VISUALC__ for it any longer
which broke compilation with it.

Restore this definition now to fix it, even though it could admittedly be
better to explicitly check for __INTELC__ in the places where we currently
only check for __VISUALC__ and reserve the latter only for the case when we
are really using MSVC.

Closes #15359.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@74640 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Document light grey colour handling in wxMSW wxBitmap::LoadFile().

For historical/compatibility reasons we handle this colour as transparent in
wxMSW when loading the bitmaps from resources, but this is rather not obvious
for the new users, so document it and provide a way of compensating for this
in the documentation as well.

Closes #15371.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@74641 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775