BHV-13973 Ignore unnecessary notification.
Currently calling setContent method for moon.Button makes additional notification.
However, this notification is useless because we can get or set content through content of Button, not client's content.

Enyo-DCO-1.1-Signed-off-by: David Um david.um@lge.com
BHV-13973 Separate contentChanged with smallChanged.
Ordinally, client is prepared for small button.
However now normal and small button both has client control.
So we do not need to tie them together

Enyo-DCO-1.1-Signed-off-by: David Um david.um@lge.com
BHV-13973 Run changed method only if user sets those properties true

Enyo-DCO-1.1-Signed-off-by: David Um david.um@lge.com
Merge pull request #1723 from enyojs/BHV-13973-davidum

Bhv 13973 Perf: moon.Button has redundant function call.

Reviewed-By: Blake Stephens (blake.stephens@lge.com)
Integrated-By: Aaron Tam (aaron.tam@lge.com)