Map the CDK atom type 'C.allene' to SYBYL 'C.1'.

Change-Id: Ic3d045d3b6cc969a1791c50bdf946b7e9d99483f
Signed-off-by: Egon Willighagen <egonw@users.sourceforge.net>
Null safe check for setting "am" bond order.

Change-Id: I57f02e16a33c9ef192461022fa0c4419dbe2ad54
Signed-off-by: Egon Willighagen <egonw@users.sourceforge.net>