Add flag to enable extra debugging features.

Setting biovel_portal_debug to true will display errors in the browser window,
making debugging more pleasant, and also keep a zipped version of Taverna
Server working directories.
Change long-dash to ASCII dash to avoid Unicode errors
Merge branch 'master' into player

* master:
  Change long-dash to ASCII dash to avoid Unicode errors
  Add flag to enable extra debugging features.

Conflicts:
	playbooks/biovel/portal/portal.yaml
WIP: Install the new portal