camtool list: introduce -describe to print camliType for each blob

Change-Id: I73630dc135a169f5b24a403b5662e7ad617cb40d
TODO: updates

Change-Id: Ie2f294e84ecea05d60680b2d1bc83123fee2947a
Merge "camtool list: introduce -describe to print camliType for each blob"
Merge branch 'master' of https://camlistore.googlesource.com/camlistore