Handle currencies with one-directional quotes and quotes < 1 in F::Q.

Some currencies quotes are one-directional, so check both directions if
necessary. Quotes with values < 1 often have too few significant digits,
so in that case use the other direction if available.

src/quotes/gnc-fq-dump

@@ -166,6 +166,15 @@ if ($exchange eq "currency") {
   while ($#ARGV >= 0) {
     my $to = shift;
     my $result = $q->currency($from, $to);
+    unless (defined($result) && $result >= 1) {
+        my $inv_res = $q->currency($to, $from);
+        if (defined($inv_res)) {
+            my $tmp = $to;
+            $to = $from;
+            $from = $tmp;
+            $result = $inv_res;
+        }
+    }
     if (defined($result)) {
       printf "1 $from = $result $to\n";
     } else {

src/quotes/gnc-fq-helper.in

@@ -350,6 +350,19 @@ while(<>) {
     last unless $to_currency;
 
     my $price = $quoter->currency($from_currency, $to_currency);
+    my $inv_price = undef;
+    #Sometimes price quotes are available in only one direction, and if the
+    #direction we asked for results in a quote < 1 we want the other direction
+    #if it's available to get more significant digits.
+    unless (defined($price) && $price > 1) {
+        $inv_price = $quoter->currency($to_currency, $from_currency);
+        if (defined($inv_price)) {
+            my $tmp = $to_currency;
+            $to_currency = $from_currency;
+            $from_currency = $tmp;
+            $price = $inv_price;
+        }
+    }
 
     $quote_data{$from_currency, "success"} = defined($price);
     $quote_data{$from_currency, "symbol"} = $from_currency;