quota: fix disabling quota, add quota tests

Update all superblock copies when disabling the quota feature.

Added basic tests for the quota feature.

Signed-off-by: Niu Yawei <niu@whamcloud.com>
Signed-off-by: Andreas Dilger <adilger@whamcloud.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/configure b/configure
index afe381f..738bd89 100755
--- a/configure
+++ b/configure
@@ -5187,6 +5187,7 @@
 
 
 QUOTA_MAN_COMMENT='.\"'
+QUOTA_CMT=
 
 
 
@@ -5309,9 +5310,11 @@
 if test "${enable_quota+set}" = set; then :
   enableval=$enable_quota; if test "$enableval" = "no"
 then
+	QUOTA_CMT=#
 	{ $as_echo "$as_me:${as_lineno-$LINENO}: result: Disabling quota support" >&5
 $as_echo "Disabling quota support" >&6; }
 else
+	QUOTA_CMT=
 	$as_echo "#define CONFIG_QUOTA 1" >>confdefs.h
 
 	{ $as_echo "$as_me:${as_lineno-$LINENO}: result: Enabling quota support" >&5
@@ -5321,7 +5324,8 @@
 fi
 
 else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: Disabling quota support by default" >&5
+  QUOTA_CMT=#
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: Disabling quota support by default" >&5
 $as_echo "Disabling quota support by default" >&6; }
 
 fi