[PATCH] Escape characters in log files

[David Phillips]

The attached patch escapes characters in log file entries.  It works
similar to Apache:

* Any non-printable characters (<= 31 or >= 127) or pipe characters
are escaped using \xhh
* Whitespace (tab, newline, vertical tab, form feed, carriage return)
characters use C-style escapes
* Double quotes or backslashes are prefixed with a backslashes

Pipes are escaped to allow for easy handling of raw logs when using
pipes as the delimiter: you can split on a pipe without any parsing.