This is the second part of two commits, the first being r403749.

Adopt the same port structure as used by the cfengine family of ports:

security/krb5 is renamed to security/krb5-114.

A brand new security/krb5 now becomes a master port for the family of
security/krb5-* ports. The default installs krb5-1.14. There is no
functional change to the port build nor does the name of the latest krb5
port and package change. Users can continue to install security/krb5
to track the latest major version of security/krb5.

Users wishing to install a specific version branch of krb5 can continue
to install any of the security/krb5-* ports or by setting KRB5_VERSION
in make.conf make.conf or including the branch on the make command line
during build:

make KRB5_VERSIN=NNN

make -V VERSIONS lists available versions.

security/krb5-appl has been updated to support this change (also fixing
a typo in the krb5-appl/Makefile).

Inspired by: sysutils/cfengine