Improvement: add support for msxml:script tags

[jakobsack]

It would be super cool if support for the msxml:script tag could be included.

Syntax is the following:

<msxsl:script language="JScript" other="arguments">
  <![CDATA[
    // javascript code, include source.js
  ]]>
</msxsl:script>

C# code could have some additional Information in XML tags, like

<msxsl:script language="C#" other="arguments">
  <msxsl:assembly name="System.Web" />
  <![CDATA[
    // C#-code, include source.cs
  ]]>
</msxml:script>

For C# I've also seen language="CSharp", I don't know which version is more common.