check_apt: fix memset

Fix memset introduced by commit 9ce7369 ("plugins/check_apt.c - Print uninitialized ereg").

Signed-off-by: Sebastian Herbszt <herbszt@gmx.de>
check_ntp: fix null termination

Fix null termination introduced by commit a04df3e ("plugins/check_ntp.c - Verify struct from response").

Signed-off-by: Sebastian Herbszt <herbszt@gmx.de>
check_real: fix null termination

Fix null termination introduced by commit b61f51a ("plugins/check_real.c - recv string null terminate").

Signed-off-by: Sebastian Herbszt <herbszt@gmx.de>
Revert "plugins/check_ntp.c - Verify struct from response"

This reverts commit a04df3e1b67dc5eab3adc202cc89901f801cdeaa.  The "fix"
was bogus in many ways and broke jitter checking.

Conflicts:
	plugins/check_ntp.c
check_ntp: Nul-terminate jitter data

Make sure the jitter response is nul-terminated before parsing the data
using string functions.
check_tcp: fix help description regarding escape option

The help description should print '\\' for backslash not just '\'.

Signed-off-by: Sebastian Herbszt <herbszt@gmx.de>
NEWS: Updating all the fixes
THANKS.in: Add new authors
Prepare release
NEWS: Modify list of changes for 2.1.1 release

Make the list of changes slightly more descriptive.
Merge branch 'maint'

* maint:
  NEWS: Modify list of changes for 2.1.1 release
  Prepare release
  THANKS.in: Add new authors
  NEWS: Updating all the fixes
  check_tcp: fix help description regarding escape option
  check_ntp: Nul-terminate jitter data
  Revert "plugins/check_ntp.c - Verify struct from response"
  check_real: fix null termination
  check_ntp: fix null termination
  check_apt: fix memset

Conflicts:
	NEWS
check_icmp: Cast size_t values for printf(3)

Convert size_t values to unsigned long for printf(3) in order to
maximize portability.