ipvs: make nlerr2syserr libnl dependent

nlerr2syserr() is only used when libnl is present... simply reflect
this in libipvs.
Fix libnl/libnl-3 logic in configure script

This patch causes the configure script to prefer libnl-3 over
libnl(1). The configure script will first check for libnl-3 and
libnl-genl-3. If both are found, use them. If not, check for
libnl(1). This is useful when building on systems that have both
libnl-3 and libnl(1) installed. It also fixes some redundant libraries
in LIBS.
Merge pull request #65 from rohara/devel

Fix libnl/libnl-3 logic in configure script
libipvs: libnl-3 include fix

when libnl-3 is present use proper include path. On most system libnl-3
include path is /usr/include/libnl3.
lib: extend command lib string parser

Extend cmd_make_strvec to support quoted string as a single slot and
commented string at the end of parsed string.
lib: cosmetics at command.c

Extend command framework to support logger and remove some dead code.
some cosmetics too.
lib: extend vty to support logger

add support to logger and some cosmetics.
autoconf: better libnl3 detection

use pkg-config facilities to append CFLAGS related instead of hardcoding
libnl3 path in configure script.
Fix memory allocation in parser

The set_value function was incorrectly using sizeof (char *) when
allocation and reallocating memory.
Fix memory allocation for MD5 digest

The vrrp_in_chk_ipsecah and vrrp_build_ipsecah functions were
incorrectly using sizeof (unsigned char *) when allocating memory for
the MD5 digest.
Fix memory leak in vty_read_config

If vty_use_backup_config returns NULL, free any memory that has been
allocated before returning.
Fix memory leak in check_include

The check_include function should always free the allocated strvec.
Check content length before allocating memory

Since extract_content_length should return 0 if CONTENT_LENGTH is not
found in the buffer, this check should be done before allocating
memory. This avoids unnecessary malloc/free calls and fixes a
potential memory leak.
Free memory if realloc fails in vty_out

If realloc returns NULL, free the original memory before returning.
Remove redundant close from vty_use_backup_config

The sav file descriptor is closed after read, so there is no need to
close it again is chmod operation fails.
Remove unnecessary netlink rtattr structures

Both netlink_link_setmode and netlink_link_add_vmac have rtattr
structures that are no needed. The addattr_l function will handle
adding the rtattr to the message. Also, this patch removes incorrect
void pointer arithmetic when setting rta_len.
vrrp: dont try to leave mcast group in unicast mode

Only perform mcast drop membership in multicast mode.
vrrp: Release and refresh properly fd hash index

Rehashing into the same loop as releasing is not really the best idea...
Reworked a little previous patch to properly release hash entries related
to the same instance and then hash it back on new fd.
vrrp: use configuration mcast group for leave message

Just forgot to use configured mcast group (v6,v4) in previous related
patch while leaving VRRP group.
Merge pull request #67 from rohara/devel

Fix various memory allocation bugs and resource leaks.