http://www.gnu.org/software/wget/manual/wget.html
- http breadth-first, ftp depth-first
- -r : recursive
- ‘-l’ : maximum depth, default 5
- '-k' : convert link for local viewing, -K to make a backup of original
- ‘-w’ a delay to lessen load of remote server
- -p; ‘--page-requisites’ download things needed for the page
- -I : include link, in comma separated list, like "/people,/cgi-bin"
- -X : exclude link
- ‘-np’ --no-parent : download from one dir not from other directories