Branch b1_4

Branch b1_4
Description: Disk fragmentation on the OSTs could eventually cause slowdowns
             after numerous create/delete cycles
Details    : The ext3 inode allocation policy would not allocate new inodes
	     very well on the OSTs because there are no new directories
	     being created.  Instead we look for groups with free space if
	     the parent directories are nearly full.
b=4466
r=alex,behlendorf