Improved error messages generated for thrown exceptions.

Suppressed "gcc -Wall -Wextra -pedantic" and "msvc /W4" warnings.
Updated and rebuilt docs.


[SVN r57451]

example/snippets/regex_grep_example_1.cpp

@@ -67,6 +67,8 @@ public:
                what[5].first - base;
       return true;
    }
+private:
+   IndexClassesPred& operator=(const IndexClassesPred&);
 };
 
 void IndexClasses(map_type& m, const std::string& file)