Enumeration: alignment

DOC_MSE_VERSION: changed in 0.3.8

Specifies how text and images are aligned in boxes.
An alignment consists of:
* horizontal alignment
* vertical alignment
* (optional) how to fill the text box
* (optional) when to fill the text box

--Script syntax--
In scripts, alignment is passed around as a string.

--Possible values--
The value is a combination of one or more flags, separated by spaces.
These flags can appear in any order.
! Value			Description
| @left@		Horizontally, align at the left
| @center@		Horizontally, align in the middle
| @right@		Horizontally, align at the right
| @top@			Vertically, align at the top
| @middle@		Vertically, align in the middle
| @bottom@		Vertically, align at the bottom
| @justify@		Fill the box exactly, by moving words apart/together.
| @justify-all@		Fill the box exactly, by moving individual characters apart/together.
| @stretch@		Fill the box exactly, by stretching the text.<br/>
			For images: stretch them, but preserve the aspect ratio.
| @if-overflow@		Only apply @justify@, @justify-all@ and @stretch@ when the box is overfull.
| @force@		Also justify text at the end of a line in a multiline text field.<br/>
			Normally only lines ending in a soft line break are justified.

--Examples--
> alignment: top left
> alignment: middle center
> alignment: top left force justify if-overflow
> alignment: { "middle" + " " + "left" }
