This change was done to avoid calling split_string() each time we want
to know the frame range. (As the frame range will be used in several
parts of the code.)
When a DocumentExporter is used to export a specific range of frames
from the CLI processor, a temporal frame tag is created, we've to delete
that tag when the DocumentExporter is destroyed.
We’ve moved the cli into its own directory (src/app/cli). Also, we’ve
added a new “--preview” parameter to know what will be done using the
given command line options.
David Capello