History was removing ?query part of the url, which could break
exhibits that are generated on the fly based on a query fragment.
Removing just the hash is sufficient to let history's html4 emulation work.
firefox has introduced "mixed active content blocking" which means
that a web page loaded with https will refuse to load http: script
links.  At the top level this can be fixed by a user choosing suitable
relative urls for exhibit scripts
(//api.simile-widgets.org/exhibit/...)  .  However, the map and time
extensions load other scripts whose urls were hard-coded to http.
Fixed by setting these urls to https if the document url is https.
updated demos to html5
Merge pull request #41 from karger/2013-09-23_https

Modified extension scriptloaders to tolerate firefox active content blocking under https
Merge pull request #42 from karger/2013-09-24_html5_demos

Updated demos to use html5 (data-ex) syntax from old (ex:)
HTML table importer: if cell is empty, don't assign empty string to field.
exporter.js assumed self-describing data which broke tsv export.
Tabular data formats require a constistent global (ordered) list of
properties to export.  Modified exporter.js to provide this and tsv.js
to rely on it.  Also fixed a small bibtex.js bug
Duplicates properties overwrite instead of merging, which is
inconsistent with how exhibit loads items.  Revised so that
second load will override if attributes are given explicitly in
the second occurrence, but will not reset attributes to default values
if they are missing in the second occurrence.
Added "id" as a core property in the exhibit database
Expand/collapse icon for facets was tiny; now click on title works too.
Warn instead of halting when one component suffers exceptions
Merge pull request #36 from karger/2013-08-24_history_query

History was removing ?query part of the url, which could break
Merge pull request #43 from karger/2013-09-25_html_table

HTML table importer: if cell is empty, don't assign empty string to field's value
Merge pull request #44 from karger/2013-09-28_exporters

exporter.js assumed self-describing data which broke tsv export.
Merge pull request #47 from karger/2013-10-01_facet_expand

Expand/collapse icon for facets was tiny; now click on title works too.
Merge pull request #48 from karger/2013-10-01_robust_elements

Warn instead of halting when one component suffers exceptions
Merge pull request #46 from karger/2013-09-29_properties

Fixed some handling of properties on data import and export. Exhibit was losing information when loading duplicate properties, and was not properly representing the "id" property as a built-in.
Improved handling of whitespace in html table importer
Added an html table exporter and corrected some exporter bugs
added one missing file