Issue 171 8

These patch enables a HAPI version of ArmZabbixAPI (named hatohol-arm-plugin-zabbix).
Users can register it from the WebUI.

Current limitation:
Items cannot be obtained.
> In this context, armPluginInfo is an input variable to be written
> in parseServerParameter().
> Actually parseServerParamter() never refers any members
> of armPluginInfo. So I think this code has no problem.

If nobody touch the member, the value will be 0 (MONITORING_SYSTEM_ZABBIX).
Yes, It doesn't affect to actual work (addTargetServer will reject it), but I think it is a wrong value in the semantic.