DTSg v0.7.0

• Added rowaggregate() method: allows for applying summary functions row-wise to a DTSg object.
• Added rowbind() method: allows for combining the rows of a DTSg object.
• Added setColNames() method: allows for renaming columns of a DTSg object.
• Added multiplier and funbyHelpers arguments to aggregate(), colapply() and subset() methods: allows for adjusting the temporal aggregation level of TALFs and for passing on user defined helper data to TALFs.
• Added multiplier also to the list of helper data passed on to TALFs.
• Added helpers argument to colapply() and rollapply() methods: controls if helper data is passed on to an applied function (makes occasionally needed anonymous function wrappers obsolete, e.g. x$colapply(fun = function(x, ...) {cumsum(x)}, funby = byYm____) can now be written as x$colapply(fun = cumsum, helpers = FALSE, funby = byYm____)).
• TALFs based on the fasttime package now also support time zones equivalent to UTC (execute grep("^(Etc/)?(UCT|UTC)$|^(Etc/)?GMT(\\+|-)?0?$", OlsonNames(), ignore.case = TRUE, value = TRUE) for a full list of supported time zones).
• Fixed that a DTSg object with only one timestamp did not set the name of its .dateTime column as expected.
• Improved vignettes and documentation.
• Minor internal code improvements.