rudimentary image preview support in the terminal window
image preview working but still experimental
fail detection in previewer
upper margin in previewer
README updated
image-preview script compatible with both Python 2 and 3
cleanup
previewer error detection
gif (without animation static) support in previewer
pattern expansion added
pattern expansion properly handled in image-preview script
cleanup
simple config for image-preview
plugin directory detection cleanup
minor tweak

The first commandline argument (i.e. the command) is previewed as well. For
these using alias -s.
README updated