Fix expension of macros in pointers with default values.

For example :

in xsl decl widget_class(%name, *clsname="%nameWidget", match="widget[@type='%name']", mode="widget_class") alias template {
| class `text **clsname` extends Widget{
content;
| }
};

widget_class('Input');

gives now :

<xsl:template match="widget[@type='Input']" mode="widget_class">
<xsl:text>class </xsl:text>
<xsl:text>InputWidget</xsl:text>
<xsl:text> extends Widget{
</xsl:text>
<xsl:text>}
</xsl:text>
</xsl:template>

Without the fix, <xsl:text>InputWidget</xsl:text> would be <xsl:text>%nameWidget</xsl:text>

include yslt.yml2

tstylesheet {
    template "/list" {
        apply "address", 0;
        | 1000 FOR I=1 TO 2 STEP 1
        | 1010 READ NAME$, STREET$, VILLAGE$
        | 1020 PRINT "INSERT INTO address (name, street, village) VALUES ('" + NAME$ + "', '" + STREET$ + "', '" + VILLAGE$ + "');"
        | 1030 NEXT I
    }
    template "address" {
        | «position() * 10 + 100» DATA "«name»", "«street»", "«village»"
    }
}