zhang_L2_boot: L2-norm based test as described by Zhang in AoV of Functional...
In erdto/TPDT: Test for paired time-resolved differences.

Description to be added.

1	zhang_F(y0, t0, M = 100, alpha = 0.05, B = 1000, 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.
`B`	[Integer] number of bootstrap realizations.
`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.