Remove non free code

[olebole]

This PR removes the code that does not follow Open Source conventions from the x11iraf package.

While it is legal to distribute all files, several Linux distributions (Debian, Fedora etc.) require that the software in their repository are conform to an Open Source definition like the one from the Open Source Initiative (OSI), which requires

• that commercial distribution is allowed
• that modifications are allowed
• that the copyright holder does not need to be informed in case of modifications.

This PR removes some functionality, namely

• the HTML widget (used f.e. for displaying the IRAF manual pages)

• the Table widget

If you think this is a significant drop, please add this in a comment.

Detailed investigation

HTML widgets

The HTML widgets were copied from NCSA Mosaic and come with the following license:

x11iraf/obm/ObmW/HTML.c

Lines 22 to 27 in d70609c

	* Licensee may make derivative works. However, if Licensee distributes *
	* any derivative work based on or derived from the Software, then *
	* Licensee will (1) notify NCSA regarding its distribution of the *
	* derivative work, and (2) clearly notify users that such derivative *
	* work is a modified version and not the original NCSA Mosaic *
	* distributed by the UI. *

The requirement to notify NCSA violates the OSI guidelines (the "desert island" test).

x11iraf/obm/ObmW/HTML.c

Lines 29 to 35 in d70609c

	* Any Licensee wishing to make commercial use of the Software should *
	* contact the UI, c/o NCSA, to negotiate an appropriate license for such *
	* commercial use. Commercial use includes (1) integration of all or *
	* part of the source code into a product for sale or license by or on *
	* behalf of Licensee to third parties, or (2) distribution of the binary *
	* code or source code to third parties that need it to utilize a *
	* commercial product sold or licensed by or on behalf of Licensee. *

Limitation to non-commercial use also violates the OSI guidelines

Table widget

The source files come with the following license:

x11iraf/obm/ObmW/Table.c

Lines 7 to 10 in d70609c

	This library is designed for free, non-commercial software creation.
	It is changeable and can be improved. The author would greatly appreciate
	any advice, new components and patches of the existing programs.
	Commercial usage is also possible with participation of the author.

Limitation to non-commercial use violates the OSI guidelines

inkstore.h

This file is not used, and has the following statement in its copyright:

x11iraf/obm/ObmW/inkstore.h

Lines 17 to 18 in d70609c

	** the disk label. You may not modify this specification without written
	** permission from Slate Corporation.

This statement (no-modify) violates the OSI guidelines

[olebole]

THis was superceded by #20