add icons, scrollbar and metronome. Sort items by apparence time.
PDF rasterization now happens on demand.
NOTE: 2 fields added in base_source, so for exisiting DB, at least the following changes are required:
ALTER TABLE base_source add column x0 integer default 0;
ALTER TABLE base_source add column y0 integer default 0;
proof of concept of loading a PDF on-demand, when client only passes the PDF url.
- cleanup for old references to /admin
- each ensemble has a allow_ondemand parameter:
  Note that this change requires the following model change:
    ALTER table base_ensemble ADD column allow_ondemand boolean default false;
    update base_ensemble set allow_ondemand = false;
- add title for on-demand pdf (last part of the URL).
add script to generate pdf metadata
Merge branch 'master' into ondemand_pdf
in progress: email confirmation
wrap up on-demand:
 - send confirmation msg when success
 - send email notification and remove source when error.
add thread level labels.
Model changes introduced in this commit:

ALTER TABLE base_labelcategory add column scope integer;
update base_labelcategory set scope=1
exclude from poll email people who have already given a consent.
when more than one script in _NB found, we use the last one instead of displaying an error. This way, we can annotate documents who contain other scripts ending in _NB,
such as documents generated with NB !
add link to add HTML
import icons for video player
Merge branch 'video'

Conflicts:
	content/data/icons/png/default_theme.png
	content/data/icons/theme_light.svg
	content/modules/dev/pers2.js
	content/modules/dev/ui.docView11.js
	content/modules/dev/ui.docView5.css
	content/modules/dev/ui.notepaneView11.js
	content/ui/admin/step22.js
add LabelCategory captions, to make labeling less error prone (short mmemonic instead of 0,1,2)
more work on youtube
add quick util to do a json dump
fix for labeling interface
hide add heml link for now
remove import causing error