Dependencies like optional and smart_ptr will no longer support C++03
therefore the new minimum language level is C++11, and all the CI jobs
for both C++98 and C++03 have been removed.
Fixed use of the deprecated top level timer class as it was causing
build problems using warnings-as-errors.
Fixed -Wdeprecated-cast in group.hpp.
Fixed -Winvalid-source-encoding in sample_new_features.cpp.
Fixed -Wself-assign-overloaded in format_test2.cpp.
These changes also allow b2 to work properly when executed from
within the format directory.
fixed a NO_LOCALE build error the benchmark build discovered,
updated ignored argument handling and fixed build warnings in clang,
changed CI build scripts to build from top level of library
On Linux, GNU's libstdc++, which is the default stdlib for icc and clang,
cannot parse the <iomanip> header in version 4.5+ (which thankfully neither
compiler advises the use of yet), as it's original C++98-friendly
implementation has been replaced with a gnu++0x implementation.
<boost/detail/iomanip.hpp> is a portable implementation of <iomanip>, providing
boost::detail::setfill, boost::detail::setbase, boost::detail::setw,
boost::detail::setprecision, boost::detail::setiosflags and
boost::detail::resetiosflags.
[SVN r68140]
