THRIFT-2729: C++ - .clang-format created and applied

Client: C++
Patch: Konrad Grochowski

make style command added
diff --git a/lib/cpp/Makefile.am b/lib/cpp/Makefile.am
index 5206db8..d0bfe62 100755
--- a/lib/cpp/Makefile.am
+++ b/lib/cpp/Makefile.am
@@ -243,3 +243,6 @@
              thrift-z.pc.in \
              thrift-qt.pc.in \
              $(WINDOWS_DIST)
+
+style-local:
+	$(CPPSTYLE_CMD)