[server][testHostResourceQueryOption] Rename: TEST_BIND -> TEST_SYNAPSE.
[server][Params] Specify 'Id' clearly to improve readability.

HostGroupSet ->
HostGroupIdSet
[server] Fix the wrong calculation of the number of triggers and hosts when the hostgroup is specfied.
Merge branch 'hostgroup-for-dashboard'
Merge branch 'master' of github.com:project-hatohol/hatohol
[server][DBClientHatohol] Add comments.
[server][ArmZabbixAPI] Eliminate disinterested host groups.

For example, 'Templates' and 'Discovered hosts' are not needed.
[server][DBClientHatohol] Use a join with the hostgroup table for getting a trigger list only when it's really needed.
[server][DBClientHatohol] Restore the indent that was mistakenly changed in the previous commit.
[server][DBClientHatohol] Use a join with the hostgroup table for getting an item list only when it's really needed.
[server][DBClientHatohol] Use a join with the hostgroup table for getting a host list only when it's really needed.
[server][DBClientHatohol] Fix a bug that passes a wrong column of host id by mistake.
[server][HostResourceQueryOption] Make a full column name with its table name.
[server][HostResourceQueryOption] Use a helper method to make code simple.
[server][FaceRest] Remove a mechanism to eliminate duplicated triggers.

Now getTriggerList never generates duplicated entries, because
DBClientHatohol doesn't use a join expect when a host group ID
is specified. Of course, in that case (using a host groupd ID),
duplicated entries are not generated in principal.
[server][FaceRest] Remove a mechanism to eliminate duplicated events.

Now getEventList never generates duplicated entries, because
DBClientHatohol doesn't use a join with the hostgroup table
expect when a host group ID is specified. Of course, in that case
(using a host groupd ID), duplicated entries are not generated
in principal.
[server][FaceRest] Remove a mechanism to eliminate duplicated items.

Now getItemList never generates duplicated entries, because
DBClientHatohol doesn't use a join with the hostgroup table
expect when a host group ID is specified. Of course, in that case
(using a host groupd ID), duplicated entries are not generated
in principal.
[server][FaceRest] Remove a class that is no longer used.
[server][HostResourceQueryOption] Rename a method to improve naturalness in the contexts.

isOnlyOneTableUsed ->
isHostgroupUsed
[server][HostResourceQueryOption] Fix a parameter name to be fit to its type.