Update strong-supervisor dependency to 0.3.0
install: Add support for Upstart 0.6

Default is 1.4, but 0.6 may be targeted with '--upstart 0.6'
install: Improve --help output
v0.1.2
Merge branch 'release/0.1.2' into production
Merge tag 'v0.1.2'

v0.1.2
Npm ignore .strong* temporary files
v0.1.3
Merge branch 'release/0.1.3' into production
Merge tag 'v0.1.3'

v0.1.3
Use .gitignore, not .npmignore

Using .npmignore disables all ignores in .gitignore, which is not so
useful.
Update README