Remove check on FTE in Expanded, don't set FTE in FTETransform

This in anticipation of strict enforcement of the FTE flag at the composite
transform level.
Update handling of FTE

If a transform sets FTE on a template, don't pass that on to subsequent
transforms. This is done by placing checks after every project call by stream
and pipe. Switch the FTE marker from metadata to a member variable of template.
Refactor FTE template exclusion

introduce a separate function to split FTE templates to a different list
Better handling of FTE exclusion during training (no reason to every include
fte templates in calls to train).
Remove File::failed, instead use direct access to fte.
Merge pull request #226 from biometrics/strict_fte

Don't pass FTE templates on to subsequent stages of a pipe/stream.