Only resize a sighting image if it exceeds the max. size. (#566)
Fix bug where image Remove link malfunctioned. (#566)
Remove client-side extraction of sighting coordinates.

Turns out the original method of extracting coordinates when the image
is uploaded to the server still works, even after resizing the image
on the client side using a canvas. (#566)
Rebuild production JS file. (#566)
Remove obsolete comment lines. (#566)
Reset the image upload dialog upon opening it.

Before, the last image uploaded would show up in the dialog upon
opening it again on the same page, such as for attaching multiple
images for a sighting. Now there is no thumbnail or filename
each time the dialog opens. (#566)
Rebuild production JS file. (#566)