Adds 'image/x-ms-bmp' as an allowed mimetype for images, and is
equivalent to 'image/bmp'.  The image module is also updated to expect
this new type.

I found an image of mine that, when uploaded, PHP thought was
'image/bmp', so it was allowed.  However, when cropping, PHP though it
was 'image/x-ms-bmp' and failed to lookup a loading/writing function.

Signed-off-by: Malf Furious <m@lfurio.us>

Adds 'image/bmp' as an allowed mimetype for images.  The image module is
also updated to expect this new type.

Signed-off-by: Malf Furious <m@lfurio.us>

Adds 'image/gif' as an allowed mimetype for images.  The image module is
also updated to expect this new type.  For background images, animated
gifs will work properly.  For head images, the cropping process
truncates the image to only one frame; this is probably for the best.

Signed-off-by: Malf Furious <m@lfurio.us>

The SQL query here, as written, was omitting 'log' type messages from
the results.

Signed-off-by: Malf Furious <m@lfurio.us>

Update all usage of saveFile() to use added saveIfFile() function,
forwarding on the convenience to model code.  Model code can pass in
file field names, rather than $_FILES arrays directly.

We can check for the existence of an object's background image by
calling getBgImg(), since it returns NULL when there is no such image.
But getHeadImg() behaves differently, returning a path to
'static/img/null.jpg' (via df.php) when there is no image, making it
more difficult to tell.  This function addresses this concern.

Added a $limit argument to specify a maximum number of results to
return.