Fixed 'txp:if_excerpt'.

A zero is a valid excerpt.

git-svn-id: http://textpattern.googlecode.com/svn/development/4.x@5333 2fea6a4d-a838-0410-917b-93a53c48e9d2
Warning icons on alert blocks

git-svn-id: http://textpattern.googlecode.com/svn/development/4.x@5334 2fea6a4d-a838-0410-917b-93a53c48e9d2
Template stuff for rending, straighten uneven indentation.

These arrays are arguments for gTxt().

git-svn-id: http://textpattern.googlecode.com/svn/development/4.x@5335 2fea6a4d-a838-0410-917b-93a53c48e9d2
A few tweaks to jQuery UI colours

git-svn-id: http://textpattern.googlecode.com/svn/development/4.x@5336 2fea6a4d-a838-0410-917b-93a53c48e9d2
Remove unused #999999 ui-icon-sprite, add a #ffffff version

git-svn-id: http://textpattern.googlecode.com/svn/development/4.x@5337 2fea6a4d-a838-0410-917b-93a53c48e9d2
Use white ui-icons on Hive messagepane alerts

git-svn-id: http://textpattern.googlecode.com/svn/development/4.x@5338 2fea6a4d-a838-0410-917b-93a53c48e9d2
Introduces tag registering.

Textpattern_Tag_Registry class can be used to sign in
tags to the registry. This allows tags use any callbacks,
offers security due to tags not being mapped directly to
functions and allows automation.

Currently any old function-to-tag mappings work as a
fallback, but will issue a notice in debugging mode.

git-svn-id: http://textpattern.googlecode.com/svn/development/4.x@5339 2fea6a4d-a838-0410-917b-93a53c48e9d2
PSR-0'd and the new 'txp:authors' tag.

To achieve lazy-loading affect, static method is used
since we don't have any type of controller system for
objects. This hopefully will be temporary.

This basically means that the tag code is not loaded at all
unless the tag is used in a template.

git-svn-id: http://textpattern.googlecode.com/svn/development/4.x@5340 2fea6a4d-a838-0410-917b-93a53c48e9d2
Merge remote-tracking branch 'upstream/master'