Refactor isolateserver.py to allow archiving multiple .isolated files at once

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In short, it would look like:
python isolateserver.py -I https:/... --isolated a.isolated --isolated 
b.isolated ...

This would greatly help performance when a builder has a lot of isolated files 
to archive that are archiving the same files, causing duplication if each one 
is being done serially or even in parallel.

This requires a few things:
- Split much of isolateserver.py isolated file processing into 
isolated_format.py to stay sane.
- Move SavedState from isolate.py into isolated_format.py.
- Make both isolate.py and isolateserver.py use isolated_format.py.
- Bonus: Make isolated_format.py be able to archive to a directory, 
isolateserver archive to an isolate server. It makes sense.

It's mostly moving a lot of code around first to make the design more sensible, 
then adding a few tens of lines to add the functionality.

Original issue reported on code.google.com by maruel@chromium.org on 27 Jun 2014 at 1:13

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Original comment by maruel@chromium.org on 27 Jun 2014 at 1:14

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Original comment by maruel@google.com on 28 Aug 2014 at 1:40

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Original comment by vadimsh@chromium.org on 5 Sep 2014 at 1:03

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Raising priority

Original comment by maruel@chromium.org on 30 Sep 2014 at 5:26

• Added labels: Priority-0
• Removed labels: Priority-2

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Original comment by vadimsh@chromium.org on 4 Nov 2014 at 7:57

• Changed state: Fixed