Java7 fixes
Squashed commit of the following:

commit 7d345bb5a63d96ee9ccd6c86a486bfe9973b4c7a
Author: Sreedhar <slakkara@codeaurora.org>
Date:   Thu Dec 19 08:59:41 2013 +0530

    libcore: fix error in javdoc todo file generation

    javadoc is faling to generate todo file due to
    relative path and this is causing sdk build to
    have spurious error. changing the path to absolute
    to ensure file created and error fixed

    Change-Id: I7c89942262434d9639b03f72fe886780f44bfba7

commit 2e884dae4bbafa09cfd84f44c7947b0233d451b4
Author: Ricardo Cerqueira <cyanogenmod@cerqueira.org>
Date:   Tue Apr 29 12:16:34 2014 +0100

    Locale: Retain compatibility with 4.4 APIs

    Wrap the new methods from change I9b2d7f8d17f970d1b57111dcfe92c16e68b0fa67
    in the previous public method.

    Fixes libcore.icu.ICUTest#test_localeFromString

    Change-Id: Icbffb5d5b55329f29c791b57d019817b5c298431

commit a34bc8e66a6bf4a4efb93a86caaadc6f1919fab7
Author: Narayan Kamath <narayan@google.com>
Date:   Fri Jan 10 14:54:31 2014 +0000

    java7: Implement new Locale APIs.

    Most validation and sanity checking is performed entirely
    in java. We use ICU only for converting back and forth
    between Locale objects and BCP-47 language tags
    (toLanguageTag & forLanguageTag).

    The new APIs also add support for script subtags and
    manipulation of unicode locale extensions.

    Note that we do not implement
    IllformedLocaleException.getErrorIndex. If anyone complains
    or if it proves useful somehow, we could plumb the information
    through from ICU if required.

    bug: 8992787
    Change-Id: I9b2d7f8d17f970d1b57111dcfe92c16e68b0fa67

commit 292286800407743e1656d8fb2c6f61f02b1e5dca
Author: Ricardo Cerqueira <cyanogenmod@cerqueira.org>
Date:   Sat Nov 2 20:25:01 2013 +0000

    art: Fix building under JDK7

commit db49e25b35aea2134db7878ccf428eb4525887b0
Author: Steve Kondik <shade@chemlab.org>
Date:   Wed Jan 9 23:43:49 2013 -0800

    Fix compilation of Enum on JDK 7

    Change-Id: I2e58b6a527e4ef1fc7ed3359b8aea88d01a031fb

    libcore: Better Enum fix for JDK 7

     * Jerome Pilliet suggests using a cast in the compareTo method instead of
       changing the field visibility. This is a much better fix.

    Change-Id: I334105e0922225512a4d0a2d4b6c9c6ec71b9c51
Add API to check certificate chain signatures

Add hidden API to check certificate chain signatures when needed. The
getCertificates implementation returns a list of all the certificates and
chains and would expect any caller interested in verifying actual chains
to call getCodeSigners instead.

We add this hidden constructor as a stop-gap until we can switch callers
over to getCodeSigners.

Bug: 13678484
Change-Id: I01cddef287767422454de4c5fd266c812a04d570