Add libvirt API ACL cases for virsh commands

Updated (2014-06-04):
Reverted change on utils_libvirtd with deprecated functions for backward compatibility. 
Rebased on top of upstream master HEAD.

Updated (2014-05-14):
Resolved virSecretPtr set coverage in PR:
https://github.com/kylazhang/tp-libvirt/pull/1

Updated (2014-05-12):
Added pool commands acl tesing case, updated the coverage statistic.

Updated (2014-05-07):
Update test case and config for libvirt ACL api testing, added total 26 commits for support coverage based on exist cases with minimum change.

### The major change in cases include:
1. Add acl config in cfg files
2. Add libvirt acl related params in virsh test cases
3. Add acl params in virsh command in virsh test cases
4. Take usage of libvirt version check as acl support is start from libvirt 1.1.1

For most not covered api, either the virsh case not in upstream yet or the exist case not direct use virsh.*command* which need update other places like virt-test repo.

We aim to full coverage of acl api in our testing, so there will be more works to do, and the following statistic shows the detail gap of the current coverage.

### Coverage statistic:
#### virDomainPtr sets:
##### Covered:
fs-trim
stop
ini-control
reset
suspend
delete
save
block-write
screenshot
send-input
core-dump
start
write
open-device
snapshot

##### Not covered:
block-read Read domain block
getattr Access domain
open-graphics Open domain graphics
open-namespace Open domain namespace
pm-control Use domain power management
read Read domain
read-secure Read secure domain
send-signal Send domain signal
migrate Migrate domain Need config on both source and target

#### virConnectPtr sets:
##### Covered:
detect-storage-pools Detect storage pools

##### Not Covered:
getattr Access connection
interface-transaction Interface transactions
pm-control Use host power management
read Read host
search-domains List domains
search-interfaces List interfaces
search-networks List networks
search-node-devices List node devices
search-nwfilters List network filters
search-secrets List secrets
search-storage-pools List storage pools
write Write host

#### virNetworkPtr sets:
##### Covered:
delete Delete network
save Save network
start Start network
stop Stop network
write Write network

##### Not Covered:
getattr Access network
read Read network

#### virNWFilterPtr sets:
##### Covered:
delete Delete network filter
save Save network filter
write Write network filter

##### Not Covered:
getattr Access network filter
read Read network filter

#### virNodeDevicePtr sets:
##### Covered:
detach Detach node device
read Read node device
start Start node device
stop Stop node device
write Write node device

##### Not Covered:
getattr Access node device

#### virStorageVolPtr sets:
##### Covered:
create Create storage volume
data-read Read storage volume data
data-write Write storage volume data
format Format storage volume
resize Resize storage volume

##### Not Covered:
delete Delete storage volume
getattr Access storage volume
read Read storage volume

#### virStoragePoolPtr sets:
##### Covered:
delete Delete storage pool
format Format storage pool
refresh Refresh storage pool
save Save storage pool
search-storage-vols List storage pool volumes
start Start storage pool
stop Stop storage pool
write Write storage pool

##### Not Covered:
getattr Access storage pool
read Read storage pool

#### virSecretPtr sets:
Resolved by PR:
https://github.com/kylazhang/tp-libvirt/pull/1

##### Covered:
delete	Delete secret
read-secure	Read secure secret
save	Save secret
write	Write secret

##### Not Covered:
getattr	Access secret
read	Read secret


**Reference:**
http://libvirt.org/acl.html#perms
http://libvirt.org/aclpolkit.html