Automated checkin: version bump for firefox 20.0b1 release. DONTBUILD CLOSED TREE a=release

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branch : GECKO200_2013022013_RELBRANCH
Added FIREFOX_20_0b1_RELEASE FIREFOX_20_0b1_BUILD2 tag(s) for changeset f9348d70933c. DONTBUILD CLOSED TREE a=release

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branch : GECKO200_2013022013_RELBRANCH