Merge pull request #8 from barnabywalters/master

Added barnabywalters as a contributor and added composer.json
fix off-by-1 err in auto_link on youtube-com links

fix off-by-1 error in auto_link on youtube-com links with manual edit for barnaby. have a few other pending fixes local but couldn't get github client to work from current internet connection. darn hotels. let's see how merging works once I get to another internet connection. :/
add auto_link <video> embed of .mp4 .mov .ogv
fix: ob1 auto_link, ellipsize_to_word. new: tw_text_proxy, tw_length_check

Fixed off by 1 errors in auto_link youtube.com linking and
ellipsize_to_word. New functions tw_text_proxy, tw_length_check.
handle YYYY-MM-DD string param in date_get_bim, date_get_ordinal_date
tw_text_proxy: https: URLs tco'd into 21 (not 20) chars, irc: URLs not tco'd.
simplify targetelement for better readability
wrote yd_to_ymd and helper ydp_to_ymd functions
avoid @-linking asciibet
citation for new gTLD problem descriptions
handle a few more whole URL ellipsing cases
auto_link: add class h-x-username for auto-linked @-names
add function tw_url_to_status_id()
update tw_text_proxy() per t.co changes to 22/23 chars

updated tw_text_proxy() per t.co changes from 20/21 to 22/23 char URLs,
because updating constants is easier than coding and depending on new
JSON caching code.
Twitter profile URLs are canonically https. ht: @jon_neal
add ctype_space(), last_character_of(). update uri_clean for https

added new functions ctype_space() from PHP, and last_character_of()
from HyperTalk.
updated uri_clean to not overescape https URLs.
add number(), y_to_days, fix ymd_to_days, simplify yd_to_days

add number() and y_to_days functions. fix ymd_to_days to use yd_to_days
(previously had a JS-only problem on DST boundaries), and fix
yd_to_days to use y_to_days simpler flow.
fix commenting in PHP-only block
substr() neg offsets, new ctype_email_local(), auto_link() avoid linking email domain as handle

fix substr() neg offsets.
add new function ctype_email_local() with minimal good enough
implementation.
a few whitespace tweaks.
fix auto_link() to avoid linking email address domain name as Twitter
handle.
ellipsize_to_word: trim extra end ws. new funcs: ymd_to_d(), get_in_reply_to_urls().

new functions ymd_to_d() and get_in_reply_to_urls() (looks for actual
"in-reply-to:" and URL in post text - Falcon backcompat).
ellipsize_to_word now trims *extra* (more than one) space/return
character at the end after truncating for any other reasons (length,
punctuation etc.)