Move generators to subdirectories.

Also move the associated JSON and logo files; and update the README
accordingly.  There will be other related scripts, particularly for the
talks series, that can use the same data, so let's keep them together.
Document SVG printing workarounds from @catern.

Summarizing commentary from @catern on IRC, 2014-08-27.
First version of ICS generator for Talks Series.
Add .gitignore.
Add iCal generator usage to README.

Also remove some dead code.
iCal generator should ignore holidays.

Category 0 has been used for this purpose.
Add calendar and event descriptions to iCal.
Handle talks sponsor info better.
First version of PHP webpage generator for Talk Series.

Generates a non-dynamic page with no links and all dates in the future.
Add auto-styling functions for talk dates on web.
Add auto-linking functions for talk notes on web.
Merge pull request #2 from timparenti/ics

First version ICS generator for talks series.

Still a lot of refactoring to do.