Add support for Ctrl-G to toggle/re-direct graphics mode

Also if the help screen is exactly the right number of lines where auto-pause
didn't leave any unviewed lines, don't pause twice.

xtrn/minesweeper/minesweeper.hlp

@@ -51,6 +51,8 @@ It's a game of quick deduction, pattern-recognition, and a little bit o' luck!
 ù 
h
cToggle
n the affected-area highlight feature with the 
hTAB
n key.
   Cycle through the available block-selector styles using 
hCtrl-S
n.
   
+ù Toggle 
h
cgraphics mode
n (when supported) with the 
hCtrl-G
n key.
+
 
hDifficulty Level
n:
 
 The difficulty level may be chosen when a new game is started (level 1 being
@@ -87,4 +89,4 @@ your terminal, you can try using these alternatives:
   
 ... or use the numeric keypad.
 
-$Id: minesweeper.hlp,v 2.0 2019/09/27 03:01:45 rswindell Exp $
+Good luck!
\ No newline at end of file

xtrn/minesweeper/minesweeper.js

@@ -1454,6 +1454,7 @@ function play()
 				console.line_counter = 0;
 				console.clear();
 				console.printfile(help_file);
+				if(console.line_counter)
 					console.pause();
 				console.clear();
 				console.aborted = false;
@@ -1463,6 +1464,11 @@ function play()
 			case '\t':
 				highlight = !highlight;
 				break;
+			case CTRL_G:	// graphics toggle/re-detect
+				graph = !graph;
+				if(graph)
+					graph = cterm.query_ctda(cterm.cterm_device_attributes.pixelops_supported);
+				// Fall-through
 			case CTRL_R:
 				console.clear();
 				full_redraw = true;