3722: more advanced re/im support
Added Seshagiri Prabhu to AUTHORS/aboutus. Welcome to SymPy!
rework real/imag processing; remove dup symbols
Merge pull request #2183 from smichr/auth

Added Seshagiri Prabhu to AUTHORS/aboutus. Welcome to SymPy!
Merge pull request #2178 from smichr/solve

3722: more advanced re/im support