[113] Initial import of the cyclewriter

Independently maintained at github.com/kristopolous/fileEngine

There is documentation at that repository with more information.

This commit also introduces the documentation for the options
that will be integrated in a subsequent commit inside of the
./sysdig -h output.
zsh completion now completes fields in -p strings

Not doing this was an oversight previously. The field completion (-p and for
filtering) now uses _describe instead of _alternatives. I should really do that
across the board, but it doesn't seem worth the effort
Merge pull request #199 from dkogan/master

zsh completion now completes fields in -p strings
[133] Implements Additional options/flags (mimic tcpdump -C file_size)

This commit introduces an engine called the "cycle writer" that is
intended to mimic tcpdump's style of captures spanning multiple files.

It supports the same arguments as tcp dump and has the same
functionality.  It was implemented independently, without viewing
any of the tcpdump code and so should be free to fall under any license.
Fix a potential crash when CWD is too long
Make sure cwd is always NULL-terminated. It always it, but a further check doesn't hurt
Once in a million years, args->arg_data_size becomes 0. When this happens and the argument being parsed is a string not coming from userspace, this causes the index dest[args->arg_data_size - 1] to 0xFFFFFFFF and causing a kernel panic.

In this fix, we exit the callback with buffer full if arg_data_size is 0, and also replace strncpy with strlcpy, avoiding the need to call strlen again.
Strip the non-numeric characters from the version prior to checking
Flags were wrongly overwritten
Merge pull request #202 from kristopolous/133-additional-options-flags-mimic-tcpdump-file_size

133 additional options flags mimic tcpdump file size
fixed a compile error under windows
merge master