#Remove L3 codes from FTI

Quick start: 

You need to download FTI first: https://github.com/leobago/fti
Then, switch to this pacakge and set the local path of FTI in run.sh (e.g, ftiDir=/home/sdi/Development/FTI/fti). 
Finally, execute run.sh. Then, the L3-related codes will be removed. 

Architecture:

All the involved files include src/interface.h, src/postckpt.c, src/postreco.c and CMakeLists.txt

1. src/interface.h: remove #include <jerasure.h> and #include <galois.h>
2. src/postckpt.c: set FTI_RSenc() to be empty. 
3. src/postreco.c: set FTI_Decode() and FTI_RecoverL3() to be empty. 
4. modify CMakeLists.txt.

Note that in the config.fti , Ckpt_L3 should be set 0, indicating that level 3 would be ignored. 
(I didn't change the checking of the users' input parameters to see if they still adopt level 3 or not, because L3 will actually be added back to FTI later. We remove it temporily here because of the copyright issue.)