Merge pull request #2 from antoneliasson/master

Exduggor till matstat (tack I).
DIGSIGMM ETI265 - Duggor med lösningar från 2013
Added OS X specific .gitignore. Added start of summary in real time programming and concurrent systems
Incremental changes
Incremental updates
Caroline wants her computer back. hehe
Fler matstatduggor. Grab it while it's hot.