Revision 1753876

DERBY-4555: Expand SYSCS_IMPORT_TABLE to accept CSV file with header lines
DERBY-6894: Enhance COLUMNINDEXES parsing for SYSCS_IMPORT_DATA

This patch was contributed by Danoja Dias (danojadias at gmail dot com)

This patch is a follow-on to revision 1752990, and ensures that the
new readHeaders() logic correctly increments the ImportReadData's
lineNumber field as it's reading the column header lines, so that if
an error occurs while reading those header lines, a reasonable line
number is reported in the error message.