FTP tests: enable text-mode for more datacheck sections
HTTP tests: use CRLF as header seperator according to RFC 2616
test suite: stop conversion of valid output to CRLF on Windows

Since the output isn't actually being written in text-mode and it
was rather used as a workaround, disable text-mode for these tests.
test 500: workaround low timer resolution on Windows

Since the timer resolution is lower, there are actually cases that
the compared values are equal. Therefore we check for previous
timestamps being greater than the current one instead.