Fixes no useful feedback about failing subcommand.
Fixes function hooks breaking when running under a path containing
spaces.
Replaced old usages with this function where possible.
Complex shell usages now use `execAndGetShell` which is equal to the
old function.
* helpers: drop incomplete GNU/kFreeBSD bits
Debian with FreeBSD kernel lacks Wayland-related packages and is not
officially supported since Jessie.
* KeybindManager: check VT ioctl availability instead of hardcoding
* plugins: add missing header for libc++ after 430778293e
src/plugins/PluginAPI.cpp:299:33: error: implicit instantiation of undefined template 'std::basic_istringstream<char>'
std::istringstream inStream(SYMBOLS);
^
/usr/include/c++/v1/iosfwd:140:32: note: template is declared here
class _LIBCPP_TEMPLATE_VIS basic_istringstream;
^
* plugins: prefer llvm-nm with Clang after 430778293e
nm: invalid option -- j
