Replace Ctrl by Meta as shortcut modifier

This paves the way to forward Ctrl to the device.

app/scrcpy.1

@@ -204,51 +204,51 @@ Default is 0 (automatic).\n
 .SH SHORTCUTS
 
 .TP
-.B Ctrl+f
+.B Meta+f
 Switch fullscreen mode
 
 .TP
-.B Ctrl+Left
+.B Meta+Left
 Rotate display left
 
 .TP
-.B Ctrl+Right
+.B Meta+Right
 Rotate display right
 
 .TP
-.B Ctrl+g
+.B Meta+g
 Resize window to 1:1 (pixel\-perfect)
 
 .TP
-.B Ctrl+x, Double\-click on black borders
+.B Meta+x, Double\-click on black borders
 Resize window to remove black borders
 
 .TP
-.B Ctrl+h, Home, Middle\-click
+.B Meta+h, Home, Middle\-click
 Click on HOME
 
 .TP
-.B Ctrl+b, Ctrl+Backspace, Right\-click (when screen is on)
+.B Meta+b, Meta+Backspace, Right\-click (when screen is on)
 Click on BACK
 
 .TP
-.B Ctrl+s
+.B Meta+s
 Click on APP_SWITCH
 
 .TP
-.B Ctrl+m
+.B Meta+m
 Click on MENU
 
 .TP
-.B Ctrl+Up
+.B Meta+Up
 Click on VOLUME_UP
 
 .TP
-.B Ctrl+Down
+.B Meta+Down
 Click on VOLUME_DOWN
 
 .TP
-.B Ctrl+p
+.B Meta+p
 Click on POWER (turn screen on/off)
 
 .TP
@@ -256,39 +256,39 @@ Click on POWER (turn screen on/off)
 Turn screen on
 
 .TP
-.B Ctrl+o
+.B Meta+o
 Turn device screen off (keep mirroring)
 
 .TP
-.B Ctrl+Shift+o
+.B Meta+Shift+o
 Turn device screen on
 
 .TP
-.B Ctrl+r
+.B Meta+r
 Rotate device screen
 
 .TP
-.B Ctrl+n
+.B Meta+n
 Expand notification panel
 
 .TP
-.B Ctrl+Shift+n
+.B Meta+Shift+n
 Collapse notification panel
 
 .TP
-.B Ctrl+c
+.B Meta+c
 Copy device clipboard to computer
 
 .TP
-.B Ctrl+v
+.B Meta+v
 Paste computer clipboard to device
 
 .TP
-.B Ctrl+Shift+v
+.B Meta+Shift+v
 Copy computer clipboard to device (and paste if the device runs Android >= 7)
 
 .TP
-.B Ctrl+i
+.B Meta+i
 Enable/disable FPS counter (print frames/second in logs)
 
 .TP