Massive but simple changes:

- Removed all tabs
- Changed all Doxygen @cond/@endcond tags with preprocessor sections, as Doxygen still has some problems when parsing this code. This also makes unmatched Doxygen sections a compilation error, which is easier to detect.

test/string_test.cpp

@@ -45,7 +45,7 @@ struct StringEqual
       if(string1.size() != string2.size())
          return false;
       return std::char_traits<typename Str1::value_type>::compare
-		  (string1.c_str(), string2.c_str(), (std::size_t)string1.size()) == 0;
+        (string1.c_str(), string2.c_str(), (std::size_t)string1.size()) == 0;
    }
 };