#642 TTipDialog does not display tips when visual styles are enabled

[Ognyan Chernokozhev]

When Windows visual styles are enabled via manifest, and application is trying to use OWLExt TTipDialog, the dialog displays a gray rectangle instead of the tip icon and text.

The resource for TTipDialog has an IDC_TIP_BULB control that does not have WS_VISIBLE style set, but apparently when visual styles are enabled, the control is made visible and is being painted over the tip text.

Note that this control serves just as a placeholder to determine the coordinates where the lightbulb bitmap is to be painted and should not be drawn.

[Ognyan Chernokozhev]

Fix for the issue applied to trunk ([r8783]), 7.0 ([r8784]), 6.44 ([r8785]) and 6.36 ([r8786]).