grim/purple-objects-docbook

updated enum.xsl to support the use of << in a value for flags values and updated blistnodeflags.enum to use it
<?xml version="1.0" encoding="UTF-8"?>
<enumeration name="ExampleEnum">
<item name="FOO" value="-1"/>
<item name="BAR" value="0"/>
<item name="BAZ"/>
</enumeration>