- #LNTYPE 2 consecutive LN behavior is removed.
- sanitization algorithm will always keep only one type of most importance,
with an exception of BOMB (which can be overlapped with INVNOTE).
- parser still guarantees that every LNSTART has LNDONE somewhere behind it.
- overlapping LNSTART/LNDONE is explicitly checked to avoid stranger result.
consequently LNSTART/LNDONE order is no longer important.
branch : 2.0