tabcontrol: Allow specified PopupMenu work when page-selector menu disabled

Original Reporter info from Mantis: AntonK

• Reporter name: Anton Kavalenka

Description:

There is TTabControl option nboHidePageListPopup which disables popping menu for page selection.
Either with this option set or not the specified PopupMenu (either in designtime or runtime) does not shown on mouse right-click or keyboard [=] context menu button.

Steps to reproduce:

Run the attached test. Try to get popup menu specified in design.
Apply the patch and test again.

Mantis conversion info:

• Mantis ID: 37171
• Version: 2.1 (SVN)
• Fixed in revision: r63287 (#39effc2a)