Changes for version 2.20

Removed “TKproE general option“ to “Include PostgreSQL support” since such support is now included in TCL 8.6.
Added the Silk icons to the inventory of icons that can be inserted into an application..
The following bugs were fixed:
1. The “States” section of the properties dialog box is no longer displayed for:
  1. Text widgets
  2. Table widgets
2. Edited text for canvas text objects now saves properly.
3. Corrected inconsistent background colors on Notebook tab properties dialog box.
4. Added a \n at the end of the code in order to properly save a TkTable widget
5. The Image and Compound options on the Notebook tab properties dialog can now properly update the properties of a ttk::notebook widget.