Mark obsolete tools more clearly

[hamogu]

A Post-Doc next door just came over and asked me "Do I really need IDL to extract spectra from marx simulations?". The answer is obviously "no", standard CIAO tools will work. However, he found the IDL tool described in the marx-toolsuit page. There are a few more obsolete tools in there (e.g. marx2img). These need to be removed or more clearly marked as obsolete.

[hamogu]

These tools should be removed (and alternatives documented) in the next major version.
Remove:

• marx2img (use marx2fits and CIAO)
• Is pfile needed for marx internally or can that be removed, too?
• marx2dpde (obsolete)
• get_hetg_spect (use CIAO)
• get_letg_spect (use CIAO)
• make_image (use marx2fits and CIAO)
• pset, plist, pwhich (use CIAO tools)
• tg_extract (use CIAO)
• rspdump, fitsdump (use CIAO dm function)

[hamogu]

Remove docs for those tools, but al;so remove tools in marx itself.