LU-1502 quota: Add basic tests for quota

LU-1502 quota: Add basic tests for quota

Fixed two minor defects in the quota code, added basic tests for
the quota feature.

Note that the m_quota test is *FAILING* on some systems, but the same
test is passing on other systems (in particular the build/test nodes):

  @@ -24,7 +24,7 @@ Pass 2: Checking directory structure
   Pass 3: Checking directory connectivity
   Pass 4: Checking reference counts
   Pass 5: Checking group summary information
  -test_filesys: 11/32768 files (18.2% non-contiguous), 5703/131072 blocks
  +test_filesys: 11/32768 files (18.2% non-contiguous), 5709/131072 blocks
   Exit status is 0

   Filesystem volume name:   <none>
  @@ -39,7 +39,7 @@ Filesystem OS type:       Linux
   Inode count:              32768
   Block count:              131072
   Reserved block count:     6553
  -Free blocks:              125369
  +Free blocks:              125363
   Free inodes:              32757
   First block:              1
   Block size:               1024
  @@ -65,8 +65,8 @@ Group 0: (Blocks 1-8192)
     Reserved GDT blocks at 3-258
     Block bitmap at 259 (+258), Inode bitmap at 260 (+259)
     Inode table at 261-516 (+260)
  -  7650 free blocks, 2037 free inodes, 2 directories
  -  Free blocks: 543-8192
  +  7644 free blocks, 2037 free inodes, 2 directories
  +  Free blocks: 549-8192
     Free inodes: 12-2048
   Group 1: (Blocks 8193-16384)
     Backup superblock at 8193, Group descriptors at 8194-8194

I'm leaving this in the "passing-on-build nodes" state, even though it
is failing on my local system, so that at least we can build and test
packages.

Signed-off-by: Niu Yawei <niu@whamcloud.com>
Signed-off-by: Andreas Dilger <andreas.dilger@intel.com>
Change-Id: If3d68075aa89d6abf0cf77be93ee3b7d927ed545