LU-2442 kernel: SLES11 performance fixes and updates

LU-2442 kernel: SLES11 performance fixes and updates

This patch completes the SLES11 SP2 kernel support. The first problem
solved is the metadata performance slow down due to the heavy dqptr_sem.
So we remove dqptr_sem (but kept in struct quota_info to keep kernel ABI
unchanged), and the functionality of this lock is implemented
by other locks:

  * i_dquot is protected by i_lock, however only this pointer, the
    content of this struct is by dq_data_lock.

  * Q_GETFMT is now protected with dqonoff_mutex instead of dqptr_sem.

The second are small optimizations block level tunable optimizations.
Added in support to simulate fail over for testing purposes. The bulk
of the changes are removal of obsolete SLES10 and syncing SLES11 SP1
kernel side support to 2.6.32.

Signed-off-by: James Simmons <uja.ornl@gmail.com>
Change-Id: I474bdd8cf8293d2918273afa074e442aafa28d4c
Reviewed-on: http://review.whamcloud.com/6168
Tested-by: Hudson
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Yang Sheng <yang.sheng@intel.com>
Reviewed-by: Lai Siyao <lai.siyao@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>