Rudimentary support for Include(name) directives in scripts.

Rudimentary support for Include(name) directives in scripts.

- Include(name) will cause the the contents of <name> from the script
  library to be inserted at that point prior to compiling the script.

- Include() may be nested, i.e., a script may include a script that
  includes another script, etc.

- A script that is intended to be included in other scripts and not to be
  listed as a selectable script for evaluation at runtime should be
  registered with OvaleScripts using:

    :RegisterScript(class, name, description, code, scriptType)

  where scriptType is anything other than "script", e.g., "include"

git-svn-id: svn://svn.curseforge.net/wow/ovale/mainline/trunk@1118 d5049fe3-3747-40f7-a4b5-f36d6801af5f