made default_chain.sh Ubuntu-compatible, added vim swap files to .gitignore
Changed /bin/bash to /usr/bin/env bash.
Merge pull request #21 from schultel/update_example

More convenient default_chain.sh
Merge branch 'master' into mod-osc

Conflicts:
	.gitignore
Merge branch 'mod-osc' of https://github.com/schultel/pisa into mod-osc