SVGHMI: Refactor the way JsonTable generate javascript code to access json data. Now support multiple assignments, used in the case of text to change both content and style on the same element.
<xsd:attribute name="Command" type="xsd:string" use="optional" default="make -C %(buildpath)s all BEREMIZSRC=%(src)s BEREMIZCFLAGS=%(cflags)s MD5=%(md5)s USE_BEREMIZ=1 FROM_BEREMIZ=1"/>