RchivalTag versions

upcoming:
	- add argument "show_time_limits" in plot_TS/DepthTS

RchivalTag_0.0.7 -- January 29, 2018 (Robert Bauer)
        - interp-function from the akima package replaced in internal calls by the approx function of the stats-package
	- added function resample_TS

RchivalTag_0.0.6 -- June 9, 2017 (Robert Bauer)
	- small bug fixed in read_histos

RchivalTag_0.0.5 -- June 8, 2017 (Robert Bauer)
	- adding average and standard deviation estimation for depth and temperature values insisde the read_histos and ts2histos functions

RchivalTag_0.0.4 -- April 25, 2017 (Robert Bauer)
	- improving performance (speed) of plot_TS/plot_DepthTS

RchivalTag_0.0.3 -- April 10, 2017 (Robert Bauer)
	- small bugs fixed in plot_TS/plot_DepthTS and read_PDT

RchivalTag_0.0.2 -- March 22, 2017 (Robert Bauer)
	- small bug in hist_tad/hist_tat functions fixed
        - adding example on back-to-back histogram for day vs night TaD-data (see: ?hist_tad)
