[Serusers] Multiple potential memory leaks in ser

[Maxim Sobolev]

Folks,

I've noticed that there are multiple potential memory leaks in SER.
The problem is that if a insert_new_lump*() function returns a NULL
for some reason (currently the only condition is memory allocation
error), it doesn't free the memory buffer passed to it and most of
the code doesn't care to deallocate that buffer after NULL is returned.
It could be easily fixed and probably needs to before the next version
is released.

Thanks!

-Maxim