Functions for working with POP3 servers

The following functions are implemented to work with POP3 servers.

ibec_pop3_OpenSession	Creates and initializes an internal object which is used to work with the POP3 protocol.
ibec_pop3_CloseSession	Destroys a POP3 object created with the ibec_pop3_OpenSession function.
ibec_pop3_Connect	Tries to establish a connection to the POP3 server.
ibec_pop3_User	Passes the user name specified for the POP3Session to the server.
ibec_pop3_Pass	Performs the POP3 PASS command specified for the POP3Session, passing to the server.
ibec_pop3_ConnectAndAuth	Performs the connection and POP3 USER and PASS commands one by one.
ibec_pop3_List	Performs the POP3 LIST command, retrieving a string with numbers and sizes (in bytes) of all of the messages available on a POP3 server.
ibec_pop3_Uidl	Performs the POP3 UIDL command, retrieving a string with numbers and unique identifiers of all of the messages available on a POP3 server.
ibec_pop3_Retr	Performs the POP3 RETR command, retrieving a string with the entire text (including header) of the message specified with MessageNumber.
ibec_pop3_Dele	This marks the message specified with MessageNumber as deleted.
ibec_pop3_Quit	This deletes all messages marked as deleted and disconnects from the POP3 mail server.
ibec_pop3_GetProperty	Returns a value of the specified property.
ibec_pop3_SetProperty	Sets a value of the specified property.