Rename kimchi.template to kimchi.substitute

This function was designed to substitute variables in HTML template strings originally
so it was named as kimchi.template, and it can be used in other scenarios, e.g. we use
it when we load plugins we have a unified URL for plugin XML files:
  /plugins/{plugin}/ui/config/tab-ext.xml
and after we have the plugins list, we can easily generate the corresponding URLs like
  /plugins/pluginA/ui/config/tab-ext.xml,
  /plugins/pluginB/ui/config/tab-ext.xml.
by list ['pluginA', 'pluginB'].
  Though it is sometimes misunderstood to be related with VM templates.
  Renamed it in this patch.

v1 -> v2:
  2a) Configurated git to use "rename" instead of "remove"&"create"
      (Thanks to Sheldon & Zheng Sheng's help)

Signed-off-by: Hongliang Wang <hlwang@linux.vnet.ibm.com>
model.host: avoid redundant libvirt lookupByName API invocation

In HostModel._get_vms_list_by_state(), it gets a list of domain objects
and extracts the names, then it traverses the names and calls
lookupByName(name) to get domain objects. This is redundant because it
has a list of domain object already.

This patch fixes the problem.

Signed-off-by: Zhou Zheng Sheng <zhshzhou@linux.vnet.ibm.com>