CSAW CTF 2014: add another possible flag for Julian Cohen

Closes #123.
CSAW CTF 2014: add weissman write-up

Closes #122.
CSAW CTF 2014: add ‘why not sftp?’ write-up

Closes #121.
CSAW CTF 2014: link to ‘psifer school’ exploit

Closes #120.
CSAW CTF 2014: clarify ‘Obscurity’ write-up
CSAW CTF 2014: add links
CSAW CTF 2014: add “We don’t know either” write-up
CSAW CTF 2014: add ‘eggshells’ write-up
CSAW CTF 2014: link to more write-ups
CSAW CTF 2014: link to more write-ups

Closes #124 and #125.
CSAW CTF 2014: clarify write-up
CSAW CTF 2014: link to writeups by @evandrix

Closes #126, #127, and #128.
CSAW CTF 2014: link to some write-ups
CSAW CTF 2014: link to ‘Obscurity’ write-up

Closes #131.
CSAW CTF 2014: link to write-ups on sugarstack.io

Closes #130.
CSAW CTF 2014: update list of completed write-ups
CSAW CTF 2014: link to write-ups by tasteless

Closes #129.
CSAW CTF 2014: link to write-ups by @shankaraman

Closes #133, #134, #135, and #136.
CSAW CTF 2014: add ‘Shameless plug’ write-up

Closes #137.
CSAW CTF 2014: minor cleanup