Average intraday time step

Signed-off-by: Oleg Komarov <o.komarov11@imperial.ac.uk>
Merge branch 'master' of git@github.com:okomarov/HFbetas
Added zip utilities to unzip selected files within a .zip

Signed-off-by: Oleg Komarov <o.komarov11@imperial.ac.uk>
Added ImportDVD for nyse taq dvds

Signed-off-by: Oleg Komarov <o.komarov11@imperial.ac.uk>