Rework wxMotif font/color inheritance so it works

like in the other ports.  Avoid setting foreground/background
color for windows and let the toolkit use the natural color.
As an intermediate step font is still explicitly set.

  Handle the cases where m_foregroundColour, m_backgroundColour ir m_font
are not initialized.

  Set default (overridable) X resources to emulate the old look.

  Unify wxMOTIF_NEW_FONT_HANDLING with wxMOTIF_USE_RENDER_TABLE.

  Minor unrelated (sizing) fixes to wxCheckListBox, wxStaticText, wxTextCtrl.

  Tagged with MOTIF_BEFORE_COLOUR_FONT_INHERITANCE before the changes.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@45312 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775