[WIP] Add a pip cache command to inspect the wheel cache

[BrownTruck]

adds a link origin file in the cache.

allows easy inspection of the wheel cache based on project names/version/last access.

$ pip cache pillow
Pillow
    - Pillow-2.8.1-cp27-none-linux_x86_64.whl
      Path: /home/xfernandez/.cache/pip/wheels/09/e3/46/5e1de20caea1bd97572a0f5adc46035689968d431270cd3397
      Size: 738.5kb - Last used: 2015-09-10 11:03:56.129241
    - Pillow-2.8.1-cp27-none-linux_x86_64.whl
      Path: /home/xfernandez/.cache/pip/wheels/16/63/c0/dc73f54d7c60d456272a53eef658d97dc2169d9aebcf4715b3
      Size: 738.5kb - Last used: 2015-09-25 14:56:28.608873
    - Pillow-2.8.2-cp27-none-linux_x86_64.whl
      Path: /home/xfernandez/.cache/pip/wheels/1b/60/09/4ec74277e8ebecb5461975edbd67082c4d4aafea8a5a2b0c6a
      Size: 738.8kb - Last used: 2015-06-30 15:39:50.618568
    - Pillow-2.9.0-cp34-cp34m-linux_x86_64.whl
      Path: /home/xfernandez/.cache/pip/wheels/7f/eb/5f/896eeaff26a20503359b552fac8b95bdde75fb97155d7935a3
      Size: 745.6kb - Last used: 2015-08-06 15:46:51.521417
    - Pillow-2.9.0-cp27-none-linux_x86_64.whl
      Path: /home/xfernandez/.cache/pip/wheels/7f/eb/5f/896eeaff26a20503359b552fac8b95bdde75fb97155d7935a3
      Size: 746.4kb - Last used: 2015-08-05 11:27:19.277327
    - Pillow-2.9.0-cp27-none-linux_x86_64.whl
      Path: /home/xfernandez/.cache/pip/wheels/95/68/ee/d6bddb5ea19b8cbe3e495fee8fb021f761596500bd5adb6956
      Original link: https://pypi.example.com/root/pypi/+f/cd4/e6286fb28e277/Pillow-2.9.0.zip#md5=cd4e6286fb28e277954c011c3ce05bc4
      Size: 746.4kb - Last used: 2015-09-28 10:07:30.812787

allows easy cleanup of old version or not used in a long time cached files

$ pip cache "pillow<2.9" --not-accessed-since=60 --remove
Deleting:

/home/xfernandez/.cache/pip/wheels/1b/60/09/4ec74277e8ebecb5461975edbd67082c4d4aafea8a5a2b0c6a/Pillow-2.8.2-cp27-none-linux_x86_64.whl
Proceed (yes/no)?

Still work in progress but already useful (at least for me), feedback is welcome.

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This was automatically migrated from #3146 to reparent it to the master branch. Please see original pull request for any previous discussion.

Original Submitter: @xavfernandez

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This change is 

[BrownTruck]

Hello!

I am an automated bot and I have noticed that this pull request is not currently able to be merged. If you are able to either merge the master branch into this pull request or rebase this pull request against master then it will eligible for code review and hopefully merging!

[pradyunsg]

@xavfernandez If you don't mind, may I take this forward?

[pradyunsg]

/ping @xavfernandez

[xavfernandez]

@pradyunsg sorry I'm swamped in Github notifications :-/
No problem if you want to take over this :)

[pradyunsg]

Closing in favour of #4685.

[lock]

This thread has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.