beanstalkd: add package

For now building from git using latest SHA (commits are relatively
infrequent).  Set priority to come up immediately after network
interfaces are brought up. Patches have been submitted upstream
(but not yet accepted) to fix:

* a somewhat cross-compile unfriendly makefile;
* a header inclusion issue which causes MUSL compilation warnings;
* using the somewhat arcane posix_fallocate() in favor of the
  more ubiquitous ftruncate() system call instead.

Hopefully the next release will include our submitted fixes and
we can transition to a numbered release.

Signed-off-by: Philip Prindeville <philipp@redfish-solutions.com>

net/beanstalkd/patches/902-replace-posix_fallocate.patch

@@ -0,0 +1,18 @@
+--- a/linux.c
++++ b/linux.c
+@@ -1,4 +1,6 @@
+ #define _XOPEN_SOURCE 600
++#include <unistd.h>
++#include <sys/types.h>
+ #include <stdint.h>
+ #include <fcntl.h>
+ #include <stdlib.h>
+@@ -19,7 +19,7 @@ static int epfd;
+ int
+ rawfalloc(int fd, int len)
+ {
+-    return posix_fallocate(fd, 0, len);
++    return ftruncate(fd, len);
+ }
+ 
+