Removed TIFF from default inline image (thanks Jeff). Only Mac iCab and OmniWeb suppo...

Removed TIFF from default inline image (thanks Jeff). Only Mac iCab and OmniWeb support inline TIFFs, and possiblly some versions of IE before 5.5. Mac versions of IE 5.1, Opera, Netscape 4 do not display inline TIFFs; IE6 also no longer displays TIFFs since dropping support for Netscape-style plugins. (I'm suprised by this because Microsoft is credited as one of the designers of the TIFF specification along with HP and Aldus as a universal image interchange format for fax and scanner images.)

git-svn-id: svn://svn.code.sf.net/p/phpwiki/code/trunk@1927 96ab9672-09ca-45d6-a79d-3d69d39ca109