Modifies "help" to support list mode. Verbose by default
Modifies "help" to support list mode. Verbose by default

Usage: "help" prints command name and help string
       "help -l" prints only the command name

Signed-off-by: Piyush Itankar <4a4ff89c9da587217bb1deb9fbe4ebeb84f02484@google.com>
Change-Id: Ia55be14064b67ab26a0a29f9e8a484ac358b0769

google/esh,google/esh