add basic scraping script to get problems from website
updated .gitignore
modify scrape.py to collect images and put everything in html/
scrape: generalise to download a range of problems
I got 99 problems, but web scrapin' aint' one.
2 fixes:
 * cast command line arg to int properly
 * get files linked to in the problem description along with images
dont fetch objects where href starts with index.php (they are other problems)
add some html static files