stringapi: Use strings for search paths

Source/cmMakeDepend.cxx

@@ -359,7 +359,7 @@ std::string cmMakeDepend::FullPath(const char* fname, const char *extraPath)
 }
 
 // Add a directory to the search path
-void cmMakeDepend::AddSearchPath(const char* path)
+void cmMakeDepend::AddSearchPath(const std::string& path)
 {
   this->IncludeDirectories.push_back(path);
 }

Source/cmMakeDepend.h

@@ -94,7 +94,7 @@ public:
   /**
    * Add a directory to the search path for include files.
    */
-  virtual void AddSearchPath(const char*);
+  virtual void AddSearchPath(const std::string&);
 
   /**
    * Generate dependencies for the file given.  Returns a pointer to