At first a warning: I don't know the Code::Blocks for Arduino environment. And I used the Arduino IDE only a short time some years ago.
A basic hint: For reporting a compiler problem please use the directions mentioned at
http://wiki.codeblocks.org/index.php/FAQ-Compiling_%28errors%29#Q:_How_do_I_troubleshoot_a_compiler_problem.3F.
Unfortunately you only added the output of the "Build messages" tab only and not the content of the "Build log" which is much more verbose.
The problem with the "undefined reference" comes up in the linking stage because the linker doesn't know where to find the compiled objects
of the classes you promised to have by including <OneWire.h> and <DallasTemperature.h>.
I don't know if it suffices to copy their sources in the library directory. Also you didn't mention what path you adapted in the build settings
of the project. As far as I remember the Arduino IDE would then build new sources in the library directory automatically.
I don't know if the Code::Blocks for Arduino environment should also do this automatically. Did Code::Blocks ever compile the library sources
into object files or a static library? In any case you must find the compiled objects anywhere in the tree if the linking stage for your project
shall have a chance to be successful.
This may not be so much useful but may give you some input to think about.
pirx