mergecsv()
takes a folder containing CSV files and merges them into a
single data.table. It is assumed that the first column of all the CSVs
contains the timestamps.
Details
All these files are read and the first column is parsed to a proper DateTime object using the formats given in the formats argu- ment. Then these dataframes are merged using the timestamp column as a common column. The merged data frame returned by the function contains the first column as the timestamps.