Fix for GCC 4.8 compilation error  #1

../../test/unittest/readertest.cpp:187:73: error: cast from type ‘const Ch*
{aka const unsigned int*}’ to type ‘void*’ casts away qualifiers [-Werror=cast-qual]
Fix for GCC 4.8 compilation warning #2

../../thirdparty/gtest/include/gtest/internal/gtest-internal.h:162:55: warning: converting ‘false’
to pointer type for argument 1 of ‘char testing::internal::IsNullLiteralHelper(testing::internal::Secret*)’

../../test/unittest/readertest.cpp:12:22: note: in expansion of macro ‘EXPECT_EQ’
  void Bool(bool b) { EXPECT_EQ(expect, b); ++step_; }
Fix for GCC 4.8 compilation warning #3

-Wnarrowing