zmailer-2.99.23 build on Linux - missed MAXPATHLEN def

[James MacKinnon <jmack@phys.ualberta.ca>]

Just a note on zmailer-2.99.23 (I think this was also left out as far
back as 2.99.15 ...) for a Linux build.

MAXPATHLEN is left undefined in transports/libta and transports/mailbox :

...
ctlopen.c: In function `ctlopen':
ctlopen.c:219: `PATH_MAX' undeclared (first use this function)
ctlopen.c:219: (Each undeclared identifier is reported only once
ctlopen.c:219: for each function it appears in.)
ctlopen.c:219: size of array `buf' has non-integer type

...
In file included from mailbox.c:67:
dotlock.c:32: `PATH_MAX' undeclared (first use this function)
dotlock.c:32: (Each undeclared identifier is reported only once
dotlock.c:32: for each function it appears in.)
dotlock.c: In function `dotunlock':
dotlock.c:72: `PATH_MAX' undeclared (first use this function)


For Linux (at least with a SlackWare dist, and under Linux v 1.3.52),

<sys/param.h>:		#define MAXPATHLEN      PATH_MAX

which is resolved in

<linux/limits.h>:	#define PATH_MAX        1024

A quick fix was to just add <linux/limits.h> to both ctlopen.c and
dotlock.c  (but there ought to be a better way to avoid an obvious
architecture dependency like this :-)

Aside from that, zmailer built without further snags.

Cheers,
--
James S. MacKinnon           Office: P-139 Avahd-Bhatia Physics Lab
Department of Physics        Voice : (403) 492-8226
University of Alberta        email : Jim.MacKinnon@Phys.UAlberta.CA
Edmonton, Canada T6G 2N5
        WWW:   http://www.phys.ualberta.ca/~jmack/jmack.html