Added  --migrate-tomcat-credentials-to-esgf flag....

This is run to move the credential files stored under tomcat's conf to
being stored under esgf's conf/tomcat directory.  This way we can feel
free to nuke tomcat wholesale and not loose our certificates.

Follows the overall concept of storing all esgf nodes' state in one
place away from the rest of the machinery.
Merge branch 'devel' into uvcdat-cmake-install