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="PurpleBlistNodeFlags">
<item name="PURPLE_BLIST_NODE_FLAG_NO_SAVE" value="1 &lt;&lt; 0"/>
</enumeration>