updatelibrary: new command that will replace misc/get_closure.pl

This command allows to selectively download from the closure library
repository the resources (.js, .css files) that are required by
the ui.

Change-Id: Ie506fe5bf0e74215d91ffbfc30ae72321b91c6c9
Merge "updatelibrary: new command that will replace misc/get_closure.pl"
closure: adding resources picked by updatelibrary

source: git rev 1389e13 on https://code.google.com/p/closure-library/

Change-Id: I7d5975c2801f24cbd368a8f048e9b073dee6d20d
encrypt: scan all meta blobs into index on start.

Yet to do: allow configuring an index besides just in-memory, and meta blob compaction.

Change-Id: I76041f1bc01487d208a0231abfef6d874ab819d9