Add 'memcheck' (valgrind) target to CMake
diff --git a/DartConfiguration.tcl b/DartConfiguration.tcl
index 63f2d3e..da4c741 100644
--- a/DartConfiguration.tcl
+++ b/DartConfiguration.tcl
@@ -1,3 +1,4 @@
 Site: localhost
 BuildName: PolarSSL-test
 CoverageCommand: /usr/bin/gcov
+MemoryCheckCommand: /usr/bin/valgrind