1GENERAL: help - give on-line help about commands, standard macros etc.

Usage: help {<topic>}

The "help" statement gives on-line help about various topics (commands, 
standard macros, variables etc.). When <topic> is specified, help will 
be given about the requested <topic>, otherwise a list of the available 
help topics is given. If there is no topic that matches unambiguously, 
a list of possible topics is shown.

Help information about macros may directly be included in the macro file:
lines starting with "##" are considered as help lines and are listed with
the "help" command.
