allocated size not reset to 0 causing NULL dereference
on call after login_close().
2) Modify login_capsize() behaviour to match manpage, allow
concatenated sizes; ie. 10m500k
This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.
Boy, I'm glad we're not using sup anymore. This update would have been
insane otherwise.
