Funny you ask as I just committed this to designer couple days ago - https://issues.jboss.org/browse/JBPM-3382 :)
It is very easy to create those yourself now in Guvnor, just use the following .wid configuration:
import org.drools.process.core.datatype.impl.type.StringDataType;
[
[
"name" : "Email",
"parameters" : [
"From" : new StringDataType(),
"To" : new StringDataType(),
"Subject" : new StringDataType(),
"Body" : new StringDataType()
],
"displayName" : "Email",
"icon" : "$protocol$://$host$/$subdomain$/rest/packages/$pkgName$/assets/defaultemailicon/binary"
],
[
"name" : "Log",
"parameters" : [
"Message" : new StringDataType()
],
"displayName" : "Log",
"icon" : "$protocol$://$host$/$subdomain$/rest/packages/$pkgName$/assets/defaultlogicon/binary"
]
]
and replace $protocol$, $host$, $subdomain$, $pkgName$ to your concrete values.
This will be available in the next designer release which should be available within next 3 weeks. If this is urgent for you, I can always craete an unofficial release which is based on master bits + this fix...let me know if you want that.
Hope this helps.