Add support for empty or null txt values.
ignore IntelliJ files and out directory
Fix AddressTest to refer to current IP address.  Add test for SPFRecord.
Merge branch 'master' of github.com:jonbodner/hopper into jonbodner-master

Conflicts:
	.gitignore
	src/test/java/biz/neustar/hopper/AddressTest.java
Merge branch 'jonbodner-master'