Gtest: update to 1.7
I2C VM: fix unsigned comparison caught by clang

Found this potential bug when working on unit tests for
OSX.
UnitTests: add tests for error correcting library
Gtest: add -Wno-missing-field-initializers to the library

This is required for gtest itself because it does not compile without
warnings as of version 1.7
Merge pull request #1395 from peabody124/gtest_1_7

Gtest 1.7 and test of ECC