BUILD/MEDIUM: standard: get rid of the last strcpy()

OpenBSD complains about our use of strcpy() in standard.c. The checks
were OK and we didn't fall into the category of "almost always misused",
but it's very simple to fix it so better do it before a problem happens.

src/standard.o(.text+0x26ab): In function `str2sa_range':
src/standard.c:718: warning: strcpy() is almost always misused, please use strlcpy()
BUILD/MEDIUM: standard: get rid of sprintf()

OpenBSD complains about the use of sprintf in human_time() :

src/standard.o(.text+0x1c40): In function `human_time':
src/standard.c:2067: warning: sprintf() is often misused, please use snprintf()

We can easily get around this by having a pointer to the end of the string and
using snprintf() instead.
BUILD/MEDIUM: cfgparse: get rid of sprintf()

A few occurrences of sprintf() were causing harmless warnings on OpenBSD :

src/cfgparse.o(.text+0x259e): In function `cfg_parse_global':
src/cfgparse.c:1044: warning: sprintf() is often misused, please use snprintf()

These ones were easy to get rid of, so better do it.
BUILD/MEDIUM: checks: get rid of sprintf()

OpenBSD complains about our use of sprintf() here :

src/checks.o(.text+0x44db): In function `process_chk':
src/checks.c:766: warning: sprintf() is often misused, please use snprintf()

This case was not really clean since the introduction of global.node BTW.
Better change the API to support a size argument in the function and enforce
the limit.
BUILD/MEDIUM: http: remove calls to sprintf()

OpenBSD complains about this use of sprintf() :

src/proto_http.o(.text+0xb0e6): In function `http_process_request':
src/proto_http.c:4127: warning: sprintf() is often misused, please use snprintf()

Here there's no risk as the strings are way shorter than the buffer size
but let's fix it anyway.
BUG/MEDIUM: systemd-wrapper: fix locating of haproxy binary

OpenBSD complains this way due to strncat() :

src/haproxy-systemd-wrapper.o(.text+0xd5): In function `spawn_haproxy':
src/haproxy-systemd-wrapper.c:33: warning: strcat() is almost always misused, please use strlcat()

In fact, the code before strncat() here is wrong, because it may
dereference a NULL if /proc/self/exe is not readable. So fix it
and get rid of strncat() at the same time.

No backport is needed.
BUG/MINOR: build: handle whitespaces in wc -l output

Certain implementations (for example ksh/OpenBSD) prefix the
'wc -l' output with whitespaces. This breaks the build since
689e4d733 ("BUILD: simplify the date and version retrieval in
the makefile").

Fix this by piping the wc output into tr -dc '0-9'.

Workaround is to build with IGNOREGIT=1.

HAProxy-1.4 is affected as well.
BUG/MINOR: Fix name lookup ordering when compiled with USE_GETADDRINFO

When compiled with USE_GETADDRINFO, make sure we use getaddrinfo(3) to
perform name lookups. On default dual-stack setups this will change the
behavior of using IPv6 first. Global configuration option
'nogetaddrinfo' can be used to revert to deprecated gethostbyname(3).