Add better images for chapter 1

Sources:

http://www.hq.nasa.gov/alsj/a11/images11.html
http://history.nasa.gov/ap11ann/kippsphotos/apollo.html
http://history.nasa.gov/SP-4406/chap1.html

p6a: http://www.hq.nasa.gov/alsj/a11/ap11-69-H-365.jpg
p6b: http://www.hq.nasa.gov/alsj/a11/ap11-69-HC-340.jpg
p6e: http://www.hq.nasa.gov/alsj/a11/ap11-S69-39961.jpg
p6g: http://history.nasa.gov/ap11ann/kippsphotos/5931.jpg
p10a: http://history.nasa.gov/SP-4406/4406-013.jpg
p10b: https://picasaweb.google.com/lh/photo/_UhCVX9DVpEkCUWiMCT0N9MTjNZETYmyPJy0liipFm0 (cropped)
Add better images for chapter 3

Sources:

p64a: http://grin.hq.nasa.gov/ABSTRACTS/GPN-2000-001274.html
p64: http://mix.msfc.nasa.gov/abstracts.php?p=1079
Add better images for chapter 4

Sources:

http://heroicrelics.org/info/f-1/f-1-thrust-chamber.html

p122a: http://heroicrelics.org/info/f-1/f-1-thrust-chamber/f-1-cut-away-thrust-chamber.jpg
Merge branch 'images'