Cause `preproc.sh` to rename all the log files before preproc'ing
Update Makefile so that commands are more obvious
Add script to generate training ASTs
Add code to process and "model" if statements

The modeling is pretty dumb at this point, so "model" is used liberally.
Update .gitignore to not include Phil Guo's data
Add rule in makefile to run code that models if statements
Fix up style in `ifs.py`