WSJT-X Merge Request #17: remove unused [-c grid] argument from ft4code & ft8code (open)

The "-c" argument is not used and not checked for. It can be removed from the usage messages from ft4code and ft8code.

Here's how the new message looks:

$ ./ft8code 

 Program ft8code:  Provides examples of message packing, LDPC(174,91) encoding,
 bit and symbol ordering, and other details of the FT8 protocol.

 Usage: ft8code "message"  # Results for specified message
        ft8code -T         # Examples of all message types
        ft8code -t         # Short format examples

Here's an example of trying to use -c (unchanged):

$ ./ft8code -c "qf22" "aa9go vk3pgo"                               
    Message                               Decoded                             Err i3.n3
----------------------------------------------------------------------------------------------------
 1. -C                                    -C                                       0.0 Free text                   

Source-encoded message, 77 bits: 
00000000000000000000000000000000000000000000000000000000000011001001001000000

14-bit CRC: 
10100011000100

83 Parity bits: 
01010111111010010110001111011100110101110110011100100001100100000100000011011111011

Channel symbols (79 tones):
  Sync               Data               Sync               Data               Sync
3140652 00000000000000000000433301315 3140652 31377334172546442551550502272 3140652

Some other attempts to be sure:

./ft8code -c "qf22" "aa9go vk3pgo"    # => "-C" (free text)
./ft8code "vk3pgo aa9go" -c qf22      # => "VK3PGO AA9GO" (std msg)
./ft8code "-c qf22 vk3pgo aa9go"      # => "-C QF22 VK3PG" (free text)
./ft8code [-c qf22] "vk3pgo aa9go"    # => "-C" (free text)
./ft8code "[-c qf22]" "vk3pgo aa9go"  # => about ft8code
./ft8code -C "QF22" "VK3PGO AA9GO"    # => "-C" (free text)
./ft8code -C "QF22 VK3PGO AA9GO"      # => about ft8code
./ft8code c "qf22" "vk3pgo aa9go"     # => "C" (Telemetry)

Thanks for the great software.

Pengo Wray VK3PGO