Add $TerminalHyperlinks system variable.

This lets you turn any reminder with an INFO "Url: ..." string
into a hyperlink on the terminal.

tests/manpage-personal-dict

@@ -402,6 +402,7 @@ Tcl
 Td
 Terbeck
 TerminalBackground
+TerminalHyperlinks
 Thronicke
 TimeSep
 TimetIs64bit

tests/test-rem

@@ -961,6 +961,14 @@ SET $ParseUntriggered 1
 REM 1 Jan 1994 MSG 1/0 = [1/0]
 EOF
 
+# Calendars with hyperlinks
+$REMIND -w,0,0 -@2 -c - 1 Jan 2020 <<'EOF' >> $OUT 2>&1
+SET $TerminalHyperlinks 1
+REM 15 INFO "Url: https://dianne.skoll.ca" MSG Hello, linky!
+REM 16 INFO "Url: https://dianne.skoll.ca" MSF Hello, linky!
+REM 17 INFO "Url: https://dianne.skoll.ca" CAL Hello, linky!
+REM 18 INFO "Url: https://dianne.skoll.ca" SPECIAL COLOR 255 0 0 Hello, linky!
+EOF
 cmp -s $OUT $CMP
 if [ "$?" = "0" ]; then
    echo "Remind:  Acceptance tests ${GRN}PASSED${NRM}"

tests/test.cmp

@@ -16759,7 +16759,10 @@ mbpad("
 bad => "ÿ"
 mbpad("ÿ", "bar", 8, 1) => Invalid multibyte sequence
 ../tests/test.rem(1891): mbpad(): Invalid multibyte sequence
-DynBuf Mallocs: 1114 mallocs; 31872128 bytes
+]8;;https://dianne.skoll.ca\Hello, linky!
+]8;;\]8;;https://dianne.skoll.ca\Hello, linky!
+]8;;\]8;;https://dianne.skoll.ca\Hello, linky!
+]8;;\DynBuf Mallocs: 1120 mallocs; 31872640 bytes
 Variable hash table statistics:
   Entries: 100146; Buckets: 87719; Non-empty Buckets: 66303
   Maxlen: 5; Minlen: 0; Avglen: 1.142; Stddev: 0.878; Avg nonempty len: 1.510
@@ -16781,7 +16784,7 @@ Expression nodes high-water: 302076
     Expression nodes leaked: 0
      Parse level high-water: 34
 Max expr node evaluations per line: 2001
-Total expression node evaluations:  106732
+Total expression node evaluations:  106733
 
 Test 2
 
@@ -24950,6 +24953,7 @@ $T
 $Tb
 $Td
 $TerminalBackground
+$TerminalHyperlinks
 $Thursday
 $TimeSep
 $TimetIs64bit
@@ -40154,3 +40158,21 @@ February 28
 -stdin-(2): `/': Division by zero
 -stdin-(2): `/': Division by zero
 # rem2ps end
++----------------------------------------------------------------------------+
+|                                January 2020‎                                |
++----------+----------+----------+----------+----------+----------+----------+
+|  Sunday‎  |  Monday‎  | Tuesday‎  |Wednesday‎ | Thursday‎ |  Friday‎  | Saturday‎ |
++----------+----------+----------+----------+----------+----------+----------+
+|          |          |          |1 ‎        |2 ‎        |3 ‎        |4 ‎        |
++----------+----------+----------+----------+----------+----------+----------+
+|5 ‎        |6 ‎        |7 ‎        |8 ‎        |9 ‎        |10 ‎       |11 ‎       |
++----------+----------+----------+----------+----------+----------+----------+
+|12 ‎       |13 ‎       |14 ‎       |15 ‎       |16 ‎       |17 ‎       |18 ‎       |
+|          |          |          |]8;;https://dianne.skoll.ca\Hello,]8;;\‎    |]8;;https://dianne.skoll.ca\Hello,]8;;\‎    |]8;;https://dianne.skoll.ca\Hello,]8;;\‎    |]8;;https://dianne.skoll.ca\Hello,]8;;\‎    |
+|          |          |          |]8;;https://dianne.skoll.ca\linky!]8;;\‎    |]8;;https://dianne.skoll.ca\linky!]8;;\‎    |]8;;https://dianne.skoll.ca\linky!]8;;\‎    |]8;;https://dianne.skoll.ca\linky!]8;;\‎    |
++----------+----------+----------+----------+----------+----------+----------+
+|19 ‎       |20 ‎       |21 ‎       |22 ‎       |23 ‎       |24 ‎       |25 ‎       |
++----------+----------+----------+----------+----------+----------+----------+
+|26 ‎       |27 ‎       |28 ‎       |29 ‎       |30 ‎       |31 ‎       |          |
++----------+----------+----------+----------+----------+----------+----------+
+

tests/test.rem

@@ -1891,6 +1891,11 @@ set a mbpad(bad, "bar", 8)
 set a mbpad(bad, "bar", 8, 1)
 
 DEBUG -x
+SET $TerminalHyperlinks 1
+REM INFO "Url: https://dianne.skoll.ca" MSG Hello, linky!
+REM INFO "Url: https://dianne.skoll.ca" MSF Hello, linky!
+REM INFO "Url: https://dianne.skoll.ca" SPECIAL COLOR 255 0 0 Hello, linky!
+
 # Don't want Remind to queue reminders
 EXIT