Make CSV-Import autodetect delimiter

Bug 1393472: Automatically detect the delimiter used to store the fields in the
csv field. The problem this should solve is that Microsoft Excel uses a
semicolon instead of a comma if the language setting of Windows is set to
German.
The first line of the csv-file contains the header fields so we use that line
to check, if it contains a comma or a semicolon since none of these appears in
the header field names itself.

Change-Id: I833041eb2169fc5ccc9557e0debf3f03c8daf7cc
Signed-off-by: Tobias Zeuch <tobias.zeuch@kit.edu>
Merge "Make CSV-Import autodetect delimiter"