Update Venueless tokens

Determine traits based on ticket type.
Set different expiry of token for miniconf only tickets.

Further badge font size adjustments

Allow all of the free text to be rendered.
Shrink font size if more than 40 characters in free text line.

Adjust badge font sizes

Allow more free text to fit on the badge.
Shrink size of name and company.

Add overlay badge support

Support so print can print only important text.

SVG modified to use display:inline/none based on overlay True/False and
a symlink to make it easy to change to a completely seperate svg if that
is not optimal.

SVG added layers to split text and graphic so graphics can be easily
hidden and printed.

Closes: #38

Update badge rendering to reflect actual render

* Switch to showing the PNG version by default, as this reflects what
will actually be rendered and sent to the printer
* Include the greyscale filter
* Include the twemoji font we'll use for rendering the badges

* Fix categories for badge icons, company names

* Company names had a misspelled filter and weren't being displayed
* Add some conditional logic so that company names don't get shown for
hobbyists or students

Add support for badge PDFs also

* Add a greyscale filter to text for more accurate preview
* Always default to SVG preview as it's the most accurate (cairo
doesn't do a great job of handling custom fonts when it converts to
png/pdf)
* Always use roboto font.

Further changes to support badge generation for lca2018

* Undo some of the debugging done early in this series of patches
* Add ability for a user to preview their own badge
* Add a template for the LCA2018 badge

Badges work by copy-pasting lca2017/pyconau2017 code around

WIP - Push for share