upgrade bultitude from 0.1.7 to 0.2.1 else compilation fail on windows 

(at least)
BTW: was already done for root project.clj [1] but not for leiningen-core [2]
[1] https://github.com/technomancy/leiningen/blob/master/project.clj
[2] https://github.com/technomancy/leiningen/blob/master/leiningen-core/project.clj

EDIT: script used to compile (place in the root dir of the cloned project ie. `leiningen\1.bat` )
```batch
rmdir /s /q target
cd leiningen-core
sed -i s/\;\;:aot/:aot/ project.clj
call lein1 clean, install
if errorlevel 1 (
  sed -i s/:aot/\;\;:aot/ project.clj 
  echo failed!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
  pause
  goto :eof
)
sed -i s/:aot/\;\;:aot/ project.clj 
cd ..
call bin\lein with-profile release uberjar
if errorlevel 1 (
  echo failed!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
  pause
  goto :eof
)
cd target
echo all done!
pause
goto :eof
```
sed is installed if you've installed git for windows ie. Git-1.8.1.2-preview20130201.exe