test: Upgrade googlemock 1.7.0 to googletest 1.8.0

Note that with the release of 1.8.0, googlemock and
googletest are unified into a single release.

test/gtest-1.8.0/googlemock/docs/Documentation.md

+This page lists all documentation wiki pages for Google Mock **(the SVN trunk version)**
+- **if you use a released version of Google Mock, please read the documentation for that specific version instead.**
+
+  * [ForDummies](ForDummies.md) -- start here if you are new to Google Mock.
+  * [CheatSheet](CheatSheet.md) -- a quick reference.
+  * [CookBook](CookBook.md) -- recipes for doing various tasks using Google Mock.
+  * [FrequentlyAskedQuestions](FrequentlyAskedQuestions.md) -- check here before asking a question on the mailing list.
+
+To contribute code to Google Mock, read:
+
+  * [DevGuide](DevGuide.md) -- read this _before_ writing your first patch.
+  * [Pump Manual](../googletest/docs/PumpManual.md) -- how we generate some of Google Mock's source files.