Make the list of spelling-correction variants available to
	ErrorDocument 300 processing through the use of the new
	envariable *VARIANTS.  The format of the envariable value is
	"uri";"reason", "uri";"reason", ... to be at least semi-consistent
	with existing multi-value field usages.  It's a little expensive
	in terms of memory, but the number of variants should be small
	and we're about to complete the request, so it seems a reasonable
	tradeoff.

PR:		2859


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@82178 13f79535-47bb-0310-9956-ffa450edef68