Merge pull request #42 from magnusjerre/iterations

Iterations
changes?
edited the design chapter
Merge pull request #43 from magnusjerre/construction_and_design

edited the design chapter
updates to chapter 4 and 9
Merge pull request #44 from magnusjerre/chapter9_doc

updates to chapter 4 and 9
Added some changes and my parts (Magnus) to the iterations
images
Merge pull request #45 from magnusjerre/chapter9_doc

images
Updated gitignore
minor changes to iterations part