Update NUnitXml.xslt to emit properties element before reason/failure (…

…#1797)

The NUnit 2.5 schema at http://nunit.org/files/testresult_schema_25.txt specifies
that the test-case element should look like this:

```xml
<xs:complexType name="test-caseType">
    <xs:sequence>
        <xs:element name="categories" type="categoriesType" minOccurs="0" maxOccurs="1" />
        <xs:element name="properties" type="propertiesType" minOccurs="0" maxOccurs="1" />
        <xs:choice>
            <xs:element name="failure" type="failureType" minOccurs="0" />
            <xs:element name="reason" type="reasonType" minOccurs="0" />
        </xs:choice>
    </xs:sequence>
    <xs:attribute name="name" type="xs:string" use="required" />
    ...
```

The usage of xs:sequence means categories, properties and failure/reason elements
need to be emitted in exactly that order.

Currently NUnitXml.xslt however emits the properties _after_ the reason element.

This fixes the xslt to emit properties in the expected order.

src/xunit.console/NUnitXml.xslt

@@ -128,14 +128,14 @@
           <xsl:value-of select="@time"/>
         </xsl:attribute>
       </xsl:if>
+      <xsl:apply-templates select="traits"/>
       <xsl:if test="reason">
         <reason>
           <message>
             <xsl:apply-templates select="reason"/>
           </message>
         </reason>
       </xsl:if>
-      <xsl:apply-templates select="traits"/>
       <xsl:apply-templates select="failure"/>
     </test-case>
   </xsl:template>
@@ -163,4 +163,4 @@
     </failure>
   </xsl:template>
 
-</xsl:stylesheet>
+</xsl:stylesheet>