Lab 1 C programming exercises to warm up

1. echoargs.c       -- just echo command line arguments.
2. echolines.c      -- just echo lines using fgets or getline.
3. echonospaces.c   -- copy a line removing spaces and echo.
4. echofirstword.c  -- copy first word on a line and echo; no leading spaces.
5. echowords.c      -- scan all words on a line and echo them.
6. argv.c           -- scan all words into an argv string array.