Support different domains

[korthout]

It may be a good idea to allow glossaries to be split-up at the domain level.

For example,

package example.communication;
/**
 * The person to send an email.
 */
@GlossaryTerm("Communication")
class Sender { }

package example.finance;
/**
 * The person to send an amount of money.
 */
@GlossaryTerm("Finance")
class Sender { }

Result:

Communication:
Sender: The person to send an email.

Finance:
Sender: The person to send an amount of money.