Add functions on Makefile for build and tag
Add functions on Makefile for build and tag

Instead copy/pasting the steps needed for building and tagging a Docker image
we are adding a function for doing it.

The function receives 4 parameters commented on the code:

- name of the service we are building
- image
- mutable image (at the moment, just a different Docker tag)
- prefix, mainly used for contrib/

martinmaly/service-catalog,vaikas-google/service-catalog,arschles/kubernetes-service-catalog,jboyd01/service-catalog,kubernetes-incubator/service-catalog,martinmaly/service-catalog,n3wscott/service-catalog,jboyd01/service-catalog,n3wscott/service-catalog,MHBauer/service-catalog,kubernetes-incubator/service-catalog,MHBauer/service-catalog,staebler/service-catalog,staebler/service-catalog,n3wscott/service-catalog,mdshuai/service-catalog,kibbles-n-bytes/service-catalog,krancour/service-catalog,krancour/service-catalog,staebler/service-catalog,duglin/service-catalog,staebler/service-catalog,mdshuai/service-catalog,kibbles-n-bytes/service-catalog,arschles/kubernetes-service-catalog,mdshuai/service-catalog,n3wscott/service-catalog,duglin/service-catalog,n3wscott/service-catalog,kubernetes-sigs/service-catalog,MHBauer/service-catalog,jboyd01/service-catalog,pmorie/service-catalog,martinmaly/service-catalog,kibbles-n-bytes/service-catalog,duglin/service-catalog,n3wscott/service-catalog,duglin/service-catalog,kubernetes-sigs/service-catalog,MHBauer/service-catalog,kibbles-n-bytes/service-catalog,staebler/service-catalog,jboyd01/service-catalog,kibbles-n-bytes/service-catalog,pmorie/service-catalog,vaikas-google/service-catalog,duglin/service-catalog,kubernetes-incubator/service-catalog,staebler/service-catalog,MHBauer/service-catalog,kubernetes-sigs/service-catalog,jboyd01/service-catalog,kubernetes-sigs/service-catalog,kubernetes-incubator/service-catalog,jboyd01/service-catalog,kubernetes-sigs/service-catalog,kubernetes-sigs/service-catalog,kibbles-n-bytes/service-catalog,pmorie/service-catalog,kubernetes-incubator/service-catalog,arschles/kubernetes-service-catalog,kubernetes-incubator/service-catalog,MHBauer/service-catalog,vaikas-google/service-catalog,duglin/service-catalog,krancour/service-catalog