Remove GetCharArg(). Organize CLI options file.

GetCharArg() was either a hack to keep from segfaulting when using
this botched option parser or it was old forgotten code - or both.

GetCharArg() was not needed because from_string() has std::string
overloaded and every GetCharArg() made its way to from_string().

Note: when using from_string() with std::string, it must be caught!

core/util/util.cpp

@@ -63,6 +63,7 @@ http://stackoverflow.com/questions/15660203/inet-pton-identifier-not-found */
 namespace i2p {
 namespace util {
 
+// TODO: this will be replaced by a real option parser soon.
 namespace config {
     std::map<std::string, std::string> mapArgs;
     std::map<std::string, std::vector<std::string> > mapMultiArgs;

core/util/util.h

@@ -38,12 +38,6 @@ namespace util
          */
         std::string GetArg(const std::string& strArg, const std::string& strDefault);
 
-        /**
-         * @return a command line argument from config::mapArgs as a C-style string
-         * @param nDefault the default value to be returned
-         */
-        const char* GetCharArg(const std::string& strArg, const std::string& nDefault);
-
         /**
          * @return true if the argument is set, false otherwise
          */