Remove spaces internally from imclass

ImageMagick seems to report the image class differently on different
platforms. See #4.
Improve README
Add iterator.jl (not yet fast) and test/readremote.jl
Add interface for 1D iteration
Require that images be StridedArrays, not AbstractArrays
Avoid immutable iterators for now and just use integer indexing

This isn't nearly so pretty, but at the moment the nicer solution
is not getting the needed performance due to limitations in inlining.
Add dispatch-based scaling/clipping/type conversion
Add display via Cairo
Merge branch 'master' of git://github.com/timholy/Images.jl
Update README
Fix widthheight
Steps towards resize support (doesn't work yet)
Support display in a pre-allocated WindowImage buffer
For now, import indexed images a direct images.

Wait for native indexed support until we have better ImageMagick
(or other IO format) support
Get imwrite working
Disable "bounds" property, plus misc. fixes
Revert added spaces in classdict entries
Merge branch 'master' of git://github.com/timholy/Images.jl