fix(view-factory): properly merge element attr overrides with surrogate values
fix(view-factory): properly merge element attr overrides with surrogate values

Behavior:
* attributes placed on the element consumer always override the
attributes from the surrogate
* classes from the element consumer and the surrogate are merged
* styles from the element consumer and the surrogate are merged; the
consumer’s styles override duplicates from the surrogate
* attributes without conflicts are always applied
* bindings from the surrogate are applied regardless
* behaviors from the surrogate are applied regardless

milunka/aurelia-templating,jw56578/templating,hitesh97/templating,JeroenVinke/templating,AshleyGrant/templating,aurelia/templating,davismj/templating,tcollard/templating,shanonvl/aurelia-templating,simudream/templating,cmichaelgraham/templating,charlespockert/templating,aurelia/templating,PWKad/templating,michaelgeorgeattard/templating