A few InstallFest changes

[akanshmurthy]

Code changes:

• People were manually typing in long commands instead of copying and pasting because they said they were following the instructions of "typing"; a simple change to copy and paste might help :)

• Open links in new tabs (people were clicking hyperlinks and were leaving the InstallFest page) rather than leave the existing page.

*less of a code change but if organizers downloaded Xcode ahead of time (lots of students were downloading XCode and doing nothing else) and have it available for install via USB drive, it would be hugely beneficial to the students