Fix the condition of confirmation on posting a tweet.
Thanks to Takashi Masuda who reported the problem.

* twittering-mode.el: Fix the condition of confirmation on posting
a tweet. The variable `twittering-request-confirmation-on-posting'
had been ignored on posting a reply. Thanks to Takashi Masuda who
reported the problem.
(twittering-edit-post-status): fix the condition of confirmation
on posting a tweet.
Support error messages formatted as JSON.

* twittering-mode.el: Support error messages formatted as JSON.
(twittering-get-error-message): receive a new argument
CONNECTION-INFO and support error messages sent as JSON.
(twittering-http-get-default-sentinel): send CONNECTION-INFO to
the function `twittering-get-error-message'.
(twittering-http-get-list-sentinel-base): likewise.
(twittering-http-post-default-sentinel): likewise.
(twittering-http-post-destroy-status-sentinel): likewise.
Parse a HTTP response body whose status code is 401 or 404.

* twittering-mode.el: Parse a HTTP response body whose status code
is 401 or 404.
(twittering-get-error-message): try to parse a HTTP respose body
whose status code is 401 or 404.
Display an error message from the 'help/configuration' API.

* twittering-mode.el: Display an error message from the
'help/configuration' API.
(twittering-update-service-configuration-sentinel): display an
error message in a HTTP response body.
Record HTTP response headers on debug mode.

* twittering-mode.el: Record HTTP response headers on debug mode.
(twittering-get-response-header): record the extracted HTTP
response header if `twittering-debug-mode' is non-nil.
Remove the function `twittering-make-field-properties'.

* twittering-mode.el: Remove the function
`twittering-make-field-properties'. It is unnecessary because
`twittering-render-a-field' automatically add a field property.
(twittering-get-common-properties): update the docstring.
(twittering-make-field-properties): removed.
(twittering-make-field-properties-of-popped-ancestors): removed.
(twittering-make-properties-of-popped-ancestors): new function.
(twittering-show-replied-statuses): use
`twittering-make-properties-of-popped-ancestors' instead of
`twittering-make-field-properties-of-popped-ancestors'.
Add a new function `twittering-make-field-id-from-id'.

* twittering-mode.el: Add a new function
`twittering-make-field-id-from-id' which generates a field ID from
a tweet ID instead of a tweet alist.
(twittering-make-field-id-from-id): new function.
(twittering-make-field-id): reimplemented with the new function
`twittering-make-field-id-from-id'.
Add a new command `retrieve-single-tweet' to `twittering-call-api'.

* twittering-mode.el: Add a new command `retrieve-single-tweet'
to the function `twittering-call-api'.
(twittering-retrieve-single-tweet-sentinel): new function.
(twittering-call-api): add `retrieve-single-tweet' as a new
command.
(twittering-make-alist-of-forbidden-tweet): new function, which
generates a dummy alist for a forbidden tweet.
(twittering-make-alist-of-non-existent-tweet): new function, which
generates a dummy alist for a non-existent tweet.
Add functions for finding a region of replied statuses.

* twittering-mode.el: Add functions for finding a region of
replied statuses with the common base status.
(twittering-replied-statuses-visible-p): add a docstring.
(twittering-get-beginning-of-visible-replied-statuses): new
function, which returns the beginning position of replied statuses
rendered by `twittering-show-replied-statuses'.
(twittering-get-end-of-visible-replied-statuses): new function,
which returns the end position of replied statuses rendered by
`twittering-show-replied-statuses'.
(twittering-hide-replied-statuses): determine a region being
deleted by using the new functions.
Fix the behavior of `twittering-replied-statuses-visible-p'.

* twittering-mode.el: Fix the behavior of the function
`twittering-replied-statuses-visible-p' on a header or a footer.
(twittering-replied-statuses-visible-p): return nil on a header or
a footer.
Add a new function `twittering-render-replied-statuses'.

* twittering-mode.el: Add a new function
`twittering-render-replied-statuses'.
(twittering-render-replied-statuses): new function, which renders
replied statuses even if some replied statuses have been already
rendered.
(twittering-show-replied-statuses): reimplemented with the new
function `twittering-render-replied-statuses'.
Regions to be redisplayed can be specified by various symbols.

* twittering-mode.el: `twittering-redisplay-status-on-each-buffer'
supports various symbols as a specifier of regions to be
redisplayed.
(twittering-redisplay-status-on-each-buffer): support other
symbols besides `need-to-be-updated' as a specifier of regions to
be redisplayed.
Support iterative retrieval of a series of replies.

* twittering-mode.el: Support iterative retrieval of a series of
replies.
(twittering-retrieve-single-tweet-sentinel): redisplay some
regions related to the retrieved status.
(twittering-render-a-tweet-with-delay): new function.
(twittering-toggle-or-retrieve-replied-statuses): new function.
(twittering-mode-map): bind "R" to the new function
`twittering-toggle-or-retrieve-replied-statuses'.
Fix a typo in 'NEWS'.
Add a function extracting a time from an ID generated by Snowflake.

* twittering-mode.el: Add a new function `twittering-id-to-time'
that extracts a corresponding time from an ID generated by
Snowflake.
(twittering-snowflake-epoch-time): new function.
(twittering-id-to-time): new function.
Use the time extracted from ID for forbidden or non-existent tweets.

* twittering-mode.el: Use the time extracted from ID for forbidden
or non-existent tweets.
(twittering-make-alist-of-forbidden-tweet): use the time extracted
from ID.
(twittering-make-alist-of-non-existent-tweet): likewise.
Update the docstring of `twittering-initial-timeline-spec-string'.

* twittering-mode.el: Update the docstring of the variable
`twittering-initial-timeline-spec-string'.
(twittering-initial-timeline-spec-string): update the docstring.