* Hailcam *
Webcam in S3
v.1

The main element is a "stream": a (looping) collection of images and/or
video. It usually corresponds to one webcam, but one can create a meta
stream if desired. A stream corresponds to a key prefix in S3, so that
all images in the stream have the same prefix. By convention hailcam
prefix ends with a slash, although it's not mandated (SHOULD).

Images and other keys are distinguished by their first letter
after the prefix. Known types:

_ - service (usually a pre-generated index for HTML browsers)
i - image
t - thumbnail
p - frame (page)

Clients are expected to use a prefix listing in S3 to find all keys
in the stream. Note that it's possible to use the same prefix listing
to find keys of a particular type.

Example:

${ROOTURL}hailcamtest/             <---- prefix for stream hailcamtest/
${ROOTURL}hailcamtest/_index.html  <---- service index
${ROOTURL}hailcamtest/i19700521    <---- image (right off cam)
${ROOTURL}hailcamtest/t19700521    <---- thumbnail for i19700521
${ROOTURL}hailcamtest/p19700521    <---- HTML frame for i19700521