Building the library fails : ''pandas/index.c: No such file or directory"
I just forked and cloned the master branch (last commit from 6th December), and building fails with the following error :

```
> python setup.py build_ext --inplace
running build_ext
building 'pandas.index' extension
gcc -pthread -fno-strict-aliasing -DNDEBUG -g -fwrapv -O2 -Wall -Wstrict-prototypes -fPIC -I/home/spiq/pandas/env/local/lib/python2.7/site-packages/numpy/core/include -Ipandas/src/klib -Ipandas/src -I/usr/include/python2.7 -c pandas/index.c -o build/temp.linux-i686-2.7/pandas/index.o
gcc: error: pandas/index.c: No such file or directory
gcc: fatal error: no input files
compilation terminated.
error: command 'gcc' failed with exit status 4
```

Any idea ?
