Merge pull request #12 from liminsun/master

BabyMEG Info
fiff info sptr
SPtr FiffInfo
replaced Buffer* to Buffer::SPtr
SPtr covariance
unix cast fixes
Memory management FiffTag* to FiffTag::SPtr
Neuromag SPtr
FiffStream* to FiffStream::SPtr
Merge branch 'master' of https://github.com/mne-tools/mne-cpp