Add level 3 libs and address build warnings

* Fix strict aliasing error in gcc

  [ Merge of http://go/wvgerrit/15856 ]

  This also ensures the alignment of 64-bit memory access in a portable
  way, without using compiler-specific mechanisms like attributes or
  platform-specific mechanisms like memalign.

  (The aliasing error does not show up in clang.)

* Return kNotSupported for non-Widevine init data

  [ Merge of http://go/wvgerrit/15853 ]

  This also improves logging for the init data parser by including a
  verbose message for non-Widevine PSSHs and by using a new IsEOF()
  method to avoid misleading "Unable to read atom size" logs.

* Cast RSA_size() to int

  [ Merge of http://go/wvgerrit/15880 ]

  It has been suggested that this may be unsigned on some versions of
  OpenSSL or BoringSSL.

* Be strict about warnings for CE CDM

  [ Merge of http://go/wvgerrit/15831 ]

  * Enable all warnings and treat warnings as errors in the CE build.
  * Fix all existing warnings (mostly unused variables, consts, and
  functions, and one signed/unsigned comparison).
  * Exclude protobuf warnings rather than maintain a divergent copy.

* Fix release build errors

  [ Merge of http://go/wvgerrit/15855 ]

* Level 3 Build With Android Emulator

  [ Merge of http://go/wvgerrit/15778 ]

  This CL rebuilds the level 3 libraries with the android emulator
  sdk_phone_*.  This seems to avoid problems with the x86 build using
  incorrect compiler flags.

  These libraries work for arm, x86, mips, arm64, and x86_64.  The level
  3 library is disabled for mips64.

  Versions:
  level3/mips/libwvlevel3.a  Level3 Library Sep 30 2015 18:29:50
  level3/arm/libwvlevel3.a  Level3 Library Sep 28 2015 13:18:25
  level3/x86/libwvlevel3.a  Level3 Library Sep 28 2015 13:08:28

Change-Id: I1e50aa78bdc84ecb905f2e55297d4f48b140341c

libwvdrmengine/cdm/core/test/license_unittest.cpp

@@ -16,7 +16,6 @@ namespace wvcdm {
 
 namespace {
 
-const uint32_t kAesBlockSize = 16;
 const std::string kAesKey = a2bs_hex("000102030405060708090a0b0c0d0e0f");
 const std::string kAesIv = a2bs_hex("000102030405060708090a0b0c0d0e0f");
 const std::string kCencInitDataHdr = a2bs_hex(