[server][DBClientHatohol] Remove unncessary c_str().

makeCondition() accepts std::string. So we don't have to use c_str().
In addition, it causes a creation of a new string object.
[Server][FaceRest] Change two maps name.

HostgroupNameMap ->
HostgroupIDNameMap

HostgroupNameMaps ->
ServerIDHostgroupIDNameMap
Merge branch 'master' into issue27-3
[Server][FaceRest] Add hostgroup information to response json data.