Add comments to array hack in gvm script. For zsh compatibility.

src/main/resources/scripts/gvm

@@ -289,9 +289,14 @@ function __gvmtool_current {
 			echo "Not using any version of ${CANDIDATE}"
 		fi
 	else
+		# The candidates are assigned to an array for zsh compliance, a list of words is not iterable
+		# Arrays are the only way, but unfortunately zsh arrays are not backward compatible with bash
+		# In bash arrays are zero index based, in zsh they are 1 based(!)
 		CANDIDATES=($(curl -s "${GVM_SERVICE}/candidates" | tr -d ","))
 		INSTALLED_COUNT=0
+		# The starts at 0 for bash, ends at the candidates array size for zsh
 		for (( i=0; i <= ${#CANDIDATES}; i++ )); do
+			# Eliminate empty entries due to incompatibility
 			if [[ -n ${CANDIDATES[$i]} ]]; then
 				__gvmtool_determine_current_version "${CANDIDATES[$i]}"
 				if [ -n "${CURRENT}" ]; then