Various testing fixes

Convert STI test images to use busybox to minimize image size.

Change STI test image default script URLs to be served by localhost (and
start a local HTTP server in the integration tests) because otherwise
changes to STI that require corresponding changes to STI scripts can't
be tested before a git merge.

Update contrib/test to be runnable from anywhere.

Run STI integration tests from contrib/test.

Add closing of Reader used when downloading scripts.
Merge pull request #163 from ncdc/sti-integration-tests

Various testing fixes
Move docker templates into templates.go
Add rm option to STI build

Add rm option to remove the previous image when doing
an incremental build. This avoids the proliferation of <none> images
that pile up with each incremental build.

Fixes #165
Make STI scripts downloading and git clone executed in parallel
Merge pull request #167 from ncdc/remove-stale-image

Add rm option to STI build
Merge pull request #157 from mfojtik/go_routines

Merged by openshift-bot
Add a multi-host demo at contrib/demo-multi
Merge pull request #171 from pmorie/demo-multi-merge

Add a multi-host demo at contrib/demo-multi
docs wip 1
docs wip 2
docs wip 3
docs wip 4
docs wip 5
docs wip 6
docs wip 7
docs wip 8