init_ccdc: initial implementation of CCDC
In dulvrq/ddl8s1ts: Map forest disturbance using Landsat 8 and Sentinel-1

initial implementation of CCDC

1	init_ccdc(doys, vals, index, col_adj, wch_start, wch_end, ccdc, rmse)

`doys`	a list of julain day
`vals`	values corresponding to `doys`.
`index`	cols for using ccdc.
`col_adj`	adjustment for cols to insert results into dataframe.
`wch_start`	numeric. Designate which is the start date of fitting in `doys`.
`wch_end`	numeric. Designate which is the end date of fitting in `doys`.
`ccdc`	(function)
`rmse`	(function)