Previously we had a template tag limit of 16. This commit lifts that
limit to support "unlimited" tags per template.

Skip already offset landmarks most efficiently when adding a new asset.

New template tags:
    __CINERA_SEARCH_URL__
    __CINERA_VOD_PLATFORM__

Database version 4

Revving resources involves hashing asset files and appending a query
string to their URLs. Additionally we monitor asset files for changes
and edit their new checksum hash into all HTML files citing them.

This commit also introduces new template tags for assets (listed below)
with which you may instruct Cinera to rev assets of your choice. There
is further information about this in the help (-h) and the README.md

Amongst other minor changes, we now support unset $XDG_CACHE_HOME and
$HOME
    - Thanks to insofaras for wordexp()

New flags:
    -Q Set query string

New template tags:
    __CINERA_ASSET__
    __CINERA_CSS__
    __CINERA_IMAGE__
    __CINERA_JS__

Renamed template tag:
    __CINERA_SEARCH__ (was __CINERA_INDEX__)

Don't \-escape anything in the index

Document server's security header (recommended) requirements

cinera_player_pre.js: Episode keyboard navigation. Also swap out A for
K, and D for J
cinera_player_pre.js: Handle the case in onRefChanged() in which the
filter_container or filterState is not present
cinera.c: Refetch quotes when processing a set of annotations >60 mins
after the last fetch

Flags:
    -w Force quote cache rebuild

-s flag sets the style / theme
Also some general code clean-up and repo organisation

README.md: Add dependency on curl

Also put the stuff in a new directory called cinera, that contains only
the files needed to get going, with example template files.

Also make hmml_to_html.c error while trying to integrate if
template.html contains the script before the player