Update first-program.md
Clarify OS X setup instructions
Merge pull request #69 from bridgethillyer/master

Clarify OS X setup instructions
Clarify OS X setup instructions
Clarify OS X setup instructions
Merge pull request #70 from bridgethillyer/master

Further clarifying OS X setup instructions
Merge pull request #68 from ldenman/patch-1

Update first-program.md
Add another lein screenshot for clarity.
Move leing screenshot location.
Updates based on OS X setup experience.
Merge pull request #71 from bridgethillyer/master

Updates to OS X setup based on setup experience.
Quote mkdir arg; for when user name has spaces
Quote mkdir arg; for when user name has spaces
Added Ubuntu setup instructions using the OS X instructions as a guide
Added the link to the docs in setup.md
Merge pull request #77 from mulchy/master

Added Ubuntu install instructions
Merge pull request #72 from alandipert/patch-1

Quote mkdir arg; for when user name has spaces
Merge pull request #73 from alandipert/patch-2

Quote mkdir arg; for when user name has spaces
Update Makefile to build boot
Increase code size in slides