Group-id bit check in ACE flag

check for specific bit instead of comparing complete number.
Ported from 1.5 : commit 44870c76b1950f85e3a2bc6b59a516993ed801a5

Signed-off-by: suhrud <supatank@in.ibm.com>
Encoding GROUP@ name in ACL
The code does not check if the group id is special id.
This leads to mapping the special "GROUP@" name to system gid 2.
Fixed to first check for special id while encoding the group name

Ported from 1.5: commit d3a14b898804585f2f594a0e4f6736769fad878d

Signed-off-by: suhrud <supatank@in.ibm.com>
Merge branch 'tp/ACE-group-id' into ibm_next_20_tmp
Merge branch 'tp/ACE-special-group' into ibm_next_20_tmp