Splunk sendemail.py modified to allow sender/from to be a variable/token

sendemail_from.py

### actual position in file may vary depending on your Splunk version, but you get the idea

*** 574,593 ****
--- 574,596 ----

      if ssContent.get('action.email.cc'):
          stringsForPost['action.email.cc'] = ssContent['action.email.cc']

      if ssContent.get('action.email.bcc'):
          stringsForPost['action.email.bcc'] = ssContent['action.email.bcc']

      if ssContent.get('action.email.to'):
          stringsForPost['action.email.to'] = ssContent['action.email.to']

+     if ssContent.get('action.email.from'):
+         stringsForPost['action.email.from'] = ssContent['action.email.from']
+
      if ssContent.get('action.email.subject'):
          stringsForPost['action.email.subject'] = ssContent['action.email.subject']

      if ssContent.get('action.email.footer.text'):
          # SPL-144752: allow footer to have no value at all if user choose to not have it.
          # This can be done by setting footer = " " (note the space in between)
          if len(ssContent['action.email.footer.text'].strip()) > 0:
              stringsForPost['action.email.footer.text'] = ssContent['action.email.footer.text']

      realizeURI = entity.buildEndpoint([ 'template', 'realize' ])