Added support for case insensitive searching of text nodes.
Make sure to set a param named "ignorecase" to "true" (noquotes)
in xpathfind after testing for a -i flag.
Now thanks to @freakabcd it also support case insensitive search:

~/dev/xpathfind p$ ./xpathfind -i "balsamiq mockups" examples/Balsamiq\ Mockups.app\ Contents\ Resources\ META-INF\ AIR\ application.xml