Use llvm-general-3.4.1.0
Add chapter binaries to .gitignore
Merge pull request #6 from Arminius/llvm-3.4

Use llvm-general-3.4.1.0
Merge pull request #7 from Arminius/gitignore-chapters

Add chapter binaries to .gitignore
note about llvm 3.4 in tutorial text