Remove unused debug flag.
Fix various problems found by cppcheck
Merge branch 'master' into ser
Add missing includes
Re-implementation of BufferManager::File

This class now doesn't have separate input and output buffers, but only one
mmaped buffer that is grown when needed. This way we only have to do a
munmap, ftruncate, mmap every buffer_size_increment calls, independent of
when we want to access already written objects.