Show a pretty progressbar when uploading and downloading an image.

Add a new module that contain generic wrapper for file and iterator, which
are used to wrap image to upload and the request body iterator in upload and
download cases repectively, to show and advance a pretty progress bar when this
laters are consumed, The progress bar is triggered by adding a --progress command
line argument to commands: image-create, image-download or image-update.

Change-Id: I2ba42fd0c58f4fa087adb568ec3f08246cae3759
bug fix: LP#1112309
blueprint: progressbar-when-uploading
Add 0.10.0 docs update

Change-Id: Ib2e75abc7d696f89d97918738bfc960cf3d1da5b
Revert 02116565d358a4fa254217779fef82b14b38d8ca

A patch slipped in that modified the default image list limit in a
backwards-incompatible way. This change reverts that patch, but
preserves some of the formatting improvements.

Change-Id: I17ae5024896ca7b1064be66b9e47653e953771d6