getfield implementation splits only on character and not string

[axel3rd]

As documented for getfield, it splits a string on a character or string.

Currently the TesTcl implementation does the split only on character because split is only on chars:

TesTcl/src/global.tcl

Lines 123 to 127 in bd55ca9

	proc ::testcl::getfield { str delim ind } {
	log::log debug "GLOBAL::getfield $str $delim $ind invoked"
	return [lindex [split $str $delim] [expr {$ind - 1}]]
	}