Added method ModifyValues2 to AdifField for modifications that must
happen after modifications to other fields. For example,
Eqsl_Qsl_Rcvd.ModifyValues2 replaces status "V" with a number of
Credit_Granted values. This must be performed after
Eqsl_QslRDate.ModifyValues is called because this method checks
for Eqsl_Qsl_Rcvd status of "V".
Qsos2.Add changed to call ModifyValues on all fields in a Qso2
object, then call ModifyValues2 on all fields in the same Qso to
ensure that situations such as above are handled.
Eqsl_Qsl_Rcvd.ModifyValues changed to ModifyValues2.
ModifyValues method added to Eqsl_QslRDate to delete the field if
Eqsl_Qsl_Rcvd is not "Y", "I", or "V".
User manual updated to describe change to Eqsl_QslRDate.