zhang_L2: L2-norm naive based test as described by Zhang in AoV of...
In toreerdmann/TPDT: Test for paired time-resolved differences.

Description to be added.

1	zhang_L2(y0, t0, M = 100, alpha = 0.05, tmin, tmax)

`yo`	[list] containing all data of one trajectory for one individual per entry.
`t0`	[list] containing the time points at which y0 were recorded with again one trajectory for one individual per entry..
`M`	[Integer] number of points for which smooth functions are discretized.
`alpha`	[numeric] significance level.
`tmin`	[numeric] beginning of time interval for which differences should be evaluated with the test.
`tmax`	[numeric] end of time interval for which differences should be evaluated with the test.