images: DecodeConfig to get the predicted width
and height after EXIF correction
search&index: add GetImageInfo and use it in search
to predict the thumbnail dimensions
http://camlistore.org/issue/115
Change-Id: I358136a2ab03ea09c8f8fd2fa0dc574921c819c5
This allows to know after a call to images.Decode if the image
was actually rotated or flipped.
Without knowing this, when making a thumbnail, it could happen
(if there was no rescaling required) that an image that needed
being rotated/flipped would not get rotated, because
useBytesUnchanged would still be true.
Change-Id: Ifc5e1e1f5a8543e6754102e3b3a685b736ae8673
This change implements rotation and flipping on images.
It can be done automatically, using the EXIF Orientation as a hint,
or optionally forced.
Change-Id: I97e887599d6a191964344e81cf8e90922313d958
mpl