compute cards_per_set as a tab separated file

Makefile

@@ -495,7 +495,11 @@ fix_eol:
 	sed -i -e 's/\x0D$$//' release/Magarena/**/*.txt
 	sed -i -e '$$a\' src/**/*.java
 
-cards_per_set.txt: cards/existing_tip_full.txt
+cards/cards_per_set.tsv: cards/existing_tip_full.txt
 	cat <(grep -o ", [A-Z0-9]* [A-Z]" $^ | cut -d' ' -f2) \
-	    <(grep -o "^[A-Z0-9]* [A-Z]"  $^ | cut -d' ' -f1) |\
-	sort | uniq -c | sort -n > $@
+	    <(grep -o "^[A-Z0-9]* [A-Z]"  $^ | cut -d' ' -f1) \
+	| sort \
+	| uniq -c \
+	| sort -n \
+	| sed 's/^ *//g;s/ /\t/' \
+	> $@