[Fix] idionsyncrets

Signed-off-by: Oleg Komarov <o.komarov11@imperial.ac.uk>
[Change] delete idiosyncret, added dailyrets; convert res to table

Signed-off-by: Oleg Komarov <o.komarov11@imperial.ac.uk>
[Add] getBetas, accepts flag to keep tall dataset, and load specific datafile

Signed-off-by: Oleg Komarov <o.komarov11@imperial.ac.uk>
[Change/add] momstrat(), rewriting expanding sp500 mom

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