Revert "Revert "String -> Any for infix_+""

This reverts commit 07ac2c5ed4715c78b0dbb3e0bf9265a9ee8217db.
infix_+ requires more thought from a typing point of view.

Revert "virtualize infix_+"

This reverts commit f591e20274ee0c3458f52262f710f0e3a94c5979.

Conflicts:
	src/main/scala/EmbeddedControls.scala