* (bug 17714) Limited TIFF upload support now built in if 'tif' extension is

* (bug 17714) Limited TIFF upload support now built in if 'tif' extension is
  enabled. Image width and height are now recognized, and when using ImageMagick,
  optional flattening to PNG or JPEG for inline display can be enabled by setting
  $wgTiffThumbnailType

By default no thumbnailing will occur; only difference from previous will be that the image width/height is detected and displayed.

Not yet implemented:
* Multi-page support
* Cleverer thumbnailing for giant files
* Thumbnailing of any sort if not using ImageMagick