[Change] sampleData: uses ismemberb() now

Signed-off-by: Oleg Komarov <o.komarov11@imperial.ac.uk>
[Change] getBetas: calls estimateBetas, more flexible syntax

Signed-off-by: Oleg Komarov <o.komarov11@imperial.ac.uk>
[Fix/Change] estimateBetas: correct length with on ret; more diagnostic messages; namesaving conventions

Signed-off-by: Oleg Komarov <o.komarov11@imperial.ac.uk>
[Change] betacomponents: handles overnight returns

Signed-off-by: Oleg Komarov <o.komarov11@imperial.ac.uk>
[Change/Add] betaPercentiles: factored beta quantiles into function

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