Change the help binding to Ctrl-g from Ctrl-h

This is necessary because some terminals send Backspace and Ctrl-h as
the same key, so Ctrl-h must be reserved for deleting. See #8.

cmd/micro/help.go

@@ -26,7 +26,7 @@ Ctrl-c:   Copy
 Ctrl-x:   Cut
 Ctrl-v:   Paste
 
-Ctrl-h:   Open help
+Ctrl-g:   Open this help screen
 
 Ctrl-u:   Half page up
 Ctrl-d:   Half page down

cmd/micro/micro.go

@@ -197,7 +197,7 @@ func main() {
 					if !canceled {
 						HandleCommand(input, view)
 					}
-				case tcell.KeyCtrlH:
+				case tcell.KeyCtrlG:
 					DisplayHelp()
 					// Make sure to resize the view if the user resized the terminal while looking at the help text
 					view.Resize(screen.Size())

cmd/micro/statusline.go

@@ -40,7 +40,7 @@ func (sline *Statusline) Display() {
 	// Add the filetype
 	file += " " + sline.view.buf.filetype
 
-	centerText := "Press Ctrl-h for help"
+	centerText := "Press Ctrl-g for help"
 
 	statusLineStyle := defStyle.Reverse(true)
 	if style, ok := colorscheme["statusline"]; ok {

cmd/micro/view.go

@@ -394,7 +394,7 @@ func (v *View) HandleEvent(event tcell.Event) {
 			v.eh.Insert(v.cursor.Loc(), " ")
 			v.cursor.Right()
 			v.UpdateLines(v.cursor.y, v.cursor.y)
-		case tcell.KeyBackspace2:
+		case tcell.KeyBackspace2, tcell.KeyBackspace:
 			// Delete a character
 			if v.cursor.HasSelection() {
 				v.cursor.DeleteSelection()