Fixed systematically loading PLC binary at startup even without -a parameter. Extended py_ext extensions instances variable description (PLCGlobalsDesc). Now contains list of variables organizd by extension, with extension name

          <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"/>