[parseopt] Refer to online documentation for command help
The online documentation (e.g. http://ipxe.org/cmd/ifopen), though not
yet complete, is far more comprehensive than could be provided within
the iPXE binary. Save around 200 bytes (compressed) by removing the
command descriptions from the interactive help, and instead referring
users directly to the web page describing the relevant command.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Command implementations tend to include a substantial amount of common
boilerplate code revolving around the parsing of command-line options
and arguments. This increases the size cost of each command.
Introduce an option-parsing library that abstracts out the common
operations involved in command implementations. This enables the size
of each individual command to be reduced, and also enhances
consistency between commands.
Total size of the library is 704 bytes, to be amortised across all
command implementations.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Michael Brown