daq_trace: Mangle output filename in multithreaded configurations

configure.ac: make C++11 optional

C++11 is optional otherwise build without C++ will fail on:
checking whether no supports C++11 features with -std=gnu++11... no
checking whether no supports C++11 features with -std=gnu++0x... no
checking whether no supports C++11 features with -std=c++11... no
checking whether no supports C++11 features with +std=c++11... no
checking whether no supports C++11 features with -h std=c++11... no
checking whether no supports C++11 features with -std=c++0x... no
checking whether no supports C++11 features with +std=c++0x... no
checking whether no supports C++11 features with -h std=c++0x... no
configure: error: *** A compiler with support for C++11 language features is required.

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>

api: Add capability flag for VXLAN decoding

api: Remove obsolete DAQ_PKT_FLAG_HW_TCP_CS_GOOD

daq_dump: Add support for dumping received packets with the 'dump-rx'…

… variable

build: Clean up some warnings reported by cppcheck

Update LibDAQ version to 2.2.2 and update the ChangeLog

Update LibDAQ version to 2.2.1 and update the ChangeLog

Update ChangeLog for LibDAQ 2.2.0 release.

Update ChangeLog for LibDAQ 2.1.0 release.