added include for cstring which should fix compile errors with c++11 and clang

7 jobs for stlTypeCheck in 72 minutes and 13 seconds
Status Name Job ID Coverage
  Test
passed clang-c++11 #8110
Linux

00:21:01

passed clang-c++98 #8112
Linux

00:17:16

passed cppcheck #8115
Linux

00:00:26

passed gcc-c++11 #8109
Linux

00:04:41

passed gcc-c++98 #8111
Linux

00:04:18

passed macos-c++11 #8113
Apple

00:09:08

passed macos-c++98 #8114
Apple

00:15:20