Don't copy files if they're older than what has already been copied

Don't copy a file again if it's not newer than whatever is already in
static/. Also, be verbose about which action was taken when -vv flag
given.

sbs

@@ -196,8 +196,21 @@ build()
 		# If file does not have .md extension, simply copy it to static/
 		extension=$(basename "$file" | awk -F'.' '{print $NF}')
 		if [ "$extension" != "md" ]; then
+			fileName=$(basename "$file")
 			subDir=$(dirname "$file" | sed "s/.*\/content//")
 			mkdir -p "static/$subDir"
+
+			# Avoid redundant copies when input file hasn't changed
+			if [ "$file" -ot "static/$subDir/$fileName" ]; then
+				if [ "$verbosity" -gt 1 ]; then
+					printf "static%s/%s up to date.\n" "$subDir" "$fileName"
+				fi
+				continue
+			fi
+
+			if [ "$verbosity" -gt 1 ]; then
+				printf "Creating: static%s/%s...\n" "$subDir" "$fileName"
+			fi
 			cp "$file" "static/$subDir"
 			continue
 		fi
@@ -323,10 +336,10 @@ case "$1" in
 		fi
 		end_s=$(date +%s)
 		if [ "$verbosity" -gt 0 ]; then
-			printf "Built %d files in %d seconds.\n" \
+			printf "Built %d pages in %d seconds.\n" \
 				$countBuilt "$(($end_s - $start_s))"
 			if [ "$countNotBuilt" -gt 0 ]; then
-				printf "%d files already up to date.\n" \
+				printf "%d pages already up to date.\n" \
 					"$countNotBuilt"
 			fi
 		fi