http://magicmonster.com/kb/prg/java/ssl/pkix_path_building_failed.html

The browser cer was exported to 
C:\Program Files (x86)\Java\jre1.8.0_31\lib\security\josm.cer
Now the keytool can import the cer with this command line.  All off the options were entered on one line but the command broke across two lines.
C:\Program Files (x86)\Java\jre1.8.0_31\lib\security>..\..\bin\keytool  -import
-alias cert.startcom.org -keystore cacerts -file josm.cer