armadillo4r 0.7.0

• Using Armadillo 15.2.1 (Medium Roast Deluxe) thanks to @conradsnicta update notification.
• Improve complex vectors/matrices copying performance by using memcpy instead of element-wise copying.
• Explicit testing with Clang and GCC compiler using C++ 14, 17, 20, and 23 standards (Armadillo 15.2.1 requires at least C++14)

armadillo4r 0.6.0

• cpp11armadillo was renamed to armadillo4r to reflect its purpose better
• supports copying complex numbers between R and C++