backup.sh v0.3.0

backup.sh v0.3.0

This release adds support for extracting and loading configuration
function dependencies. Now, if a configuration function declared in a
Backupfile calls another function (not necessarily prefixed with the job
name) it will also be loaded.

Note that caution must be exercised to avoid overwriting backup.sh
internal functions. This may be changed in future to require function
names be prefixed with a namespace string to be considered for loading.