Styling for jQuery UI input spinners

git-svn-id: http://textpattern.googlecode.com/svn/development/4.x@5348 2fea6a4d-a838-0410-917b-93a53c48e9d2
has_privs() doesn't query DB if unnecessary.

git-svn-id: http://textpattern.googlecode.com/svn/development/4.x@5349 2fea6a4d-a838-0410-917b-93a53c48e9d2
has_privs() uses strict comparison w/ whitespace support.

git-svn-id: http://textpattern.googlecode.com/svn/development/4.x@5350 2fea6a4d-a838-0410-917b-93a53c48e9d2
has_privs() is strict with usernames.

git-svn-id: http://textpattern.googlecode.com/svn/development/4.x@5351 2fea6a4d-a838-0410-917b-93a53c48e9d2
get_safe_image_types() doesn't require its own user check.

git-svn-id: http://textpattern.googlecode.com/svn/development/4.x@5352 2fea6a4d-a838-0410-917b-93a53c48e9d2
Drop alternative syntax from http_accept_format().

Returns a boolean, allowing us to have no separate
condition.

git-svn-id: http://textpattern.googlecode.com/svn/development/4.x@5353 2fea6a4d-a838-0410-917b-93a53c48e9d2
Convert parse_textpack() into a class.

Textpack parsing is now handled by the
Textpattern_Textpack_Parser class.

git-svn-id: http://textpattern.googlecode.com/svn/development/4.x@5354 2fea6a4d-a838-0410-917b-93a53c48e9d2
Register the 'comments_help' tag; add the tag outliers from comment.php to the registry for completeness.

git-svn-id: http://textpattern.googlecode.com/svn/development/4.x@5355 2fea6a4d-a838-0410-917b-93a53c48e9d2
Merge remote-tracking branch 'upstream/master'