Have cooling-type use the common argument.hpp

The cooling-type application should use the common
header file for the ArgumentParser class now that one
is available.

Also fixed where a static ArgumentParser constant was
being initialized.

Change-Id: I1fb0dfe3bd0c6e0200ad7c718ef2a3def5476f3f
Signed-off-by: Matt Spinler <spinler@us.ibm.com>
diff --git a/control/argument.cpp b/control/argument.cpp
index 2852dee..d9b832d 100644
--- a/control/argument.cpp
+++ b/control/argument.cpp
@@ -82,6 +82,7 @@
 
 const char* ArgumentParser::optionstr = "ich?";
 
+const std::string ArgumentParser::true_string = "true";
 const std::string ArgumentParser::empty_string = "";
 
 }