parsers.c: fix integer overflows
thanks to zzuf for helping finding those
created new head% local deleted a file, remote removedabort: outstanding uncommitted changesresolving manifestsremoving a0 files updated, 0 files merged, 1 files removed, 0 files unresolved(branch merge, don't forget to commit)% should show a as removedR a% manifest. should not have a:b