A condition is formed by:
<tag> <op> <value>
<tag> is the normal yambar tag. <op> is one of '==', '!=', '<', '<=', '>', or
'>='. <value> is what you wish to compare it to.
'boolean' tags must be used directly. They falsehood is matched with '~':
<tag>
~<tag>
Finally, to match an empty string, one must use ' "" ':
<tag> <op> ""
This is a configuration that is expected to validate, and to exercise
as much as possible of the code up until validation has
completed. That is, as much as possible of the configuration
validation code.
It currently instantiates all modules, but not yet all particles and
decorations.
