fix many compilation warnings about static variables used by non-static functions

[CC] plc_main.c -> plc_main.o
/tmp/be/build/plc_main.c:396:40: warning: ?LogBuff? is static but used in inline function ?copy_from_log? which is not static
memcpy((char*)buf + remaining, LogBuff[level], size - remaining);
^
/tmp/be/build/plc_main.c:395:22: warning: ?LogBuff? is static but used in inline function ?copy_from_log? which is not static
memcpy(buf, &LogBuff[level][buffpos], remaining);
^
...

^
/tmp/be/build/plc_debugger.c:825:20: warning: ?retain_offset? is static but used in inline function ?BufferIterator? which is not static
Retain(retain_offset, size, real_value_p);
^
/tmp/be/build/plc_debugger.c:823:47: warning: ?retain_offset? is static but used in inline function ?BufferIterator? which is not static
unsigned int next_retain_offset = retain_offset + size;
^
^

from weakref import ref

class POULibrary:
    def __init__(self, CTR, LibName, TypeStack):
        from PLCControler import PLCControler
        self.CTR = ref(CTR)
        self.LibName = LibName
        self.LibraryControler = PLCControler()
        self.LibraryControler.OpenXMLFile(self.GetLibraryPath())
        self.LibraryControler.ClearConfNodeTypes()
        self.LibraryControler.AddConfNodeTypesList(TypeStack)
        self.program = None;

    def GetSTCode(self):
        if not self.program:
            self.program = self.LibraryControler.GenerateProgram()[0]+"\n"
        return self.program 

    def GetName(self):
        return self.LibName

    def GetCTR(self):
        return self.CTR()
        
    def GetTypes(self):
        return {"name" : self.GetName(), "types": self.LibraryControler.Project}

    def GetLibraryPath(self):
        raise Exception("Not implemented")

    def Generate_C(self, buildpath, varlist, IECCFLAGS):
        # Pure python or IEC libs doesn't produce C code
        return ((""), [], False), ""