Reduce sensitivity to data formatting problems in data_import function in com_mseg.py
The data_import function currently skips any lines that do not conform to the format specified by the data type based on the first line of the file. This approach ensures that blank lines or lines that are commentary about the file and not actual data are skipped, but creates a risk that if a line is not the correct length due to an unexpected formatting anomaly (e.g., single instead of double quotes around strings), that line will be skipped with no warning. This problem could be avoided with a test and/or with some kind of warning message that prints to STDOUT when there is an anomalous line length, particularly if it appears in the middle of the file or if it more than a certain number of lines are skipped.