use calloc() to initialize masternotifier
write dummy data (with correct size) into pipe

CID:27772
check for head!=NULL before dereferencing it

CID:27747
CID:27771
assure that we really have a dummy argument

sender_getlasterror() currently returns a generic last error from
the system.
in a better world, it might return only the last error specific to the
given instance, but not yet.

CID:27761
loop until _this->head != NULL
lock x_connlock during ctor

for consistency, protect access of x_fd, x_port and x_keeprunning
with a mutex, even though three is no other thread during constructor.

CID:27748
CID:27749
CID:27750
check hostname before opening socket

so if hostname fails, we don't leak the socket resource

CID:27767
initializing sockaddr_in to 0

using memset()

CID:27777
added coverity model

to suppress false positives.

currently: sys_closesocket() closes the filedescriptor

CID:27764
CID:27767
initialize sockaddr_in to zero

CID:27773
CID:27774
CID:27775
CID:27776
CID:27778
CID:27779
CID:27780
added coverity exception for DEBUG( ) accessing freed pointer

DEBUG() only prints - and we want to see the address that was freed.

CID:27781
x->x_sr can never be NULL, it's an array

but the index needs to be checked!

CID:27755
CID:27760
check whether sockfd is <0 (on error)

socket() returns <0 on error, in which case we have to stop.

CID:27754
fallback to broadcast mode if socket2index returns <0

CID:27753
include <string.h> for memset
use unsigned for array indices (client id)
do not initialize "but"-value, it's set anyhow
removed double assignment to same variable

CID:27746
using unsigned int whenever possible for connection-indices
indentation