v0.11.0 (Lizard)

• allow return values from functions decorated with @trace in Python bindings
• allow conditional build of TCP listener
• enable forceful compilation using C compiler (using 0DFORCE_C_COMPILATION=ON cmake flag)
• allow disable multithreading support (using -DENABLE_THREADS=OFF cmake flag)
• fix MacOS build
• add on-client-connected callback to TCP listener
• improve test suite
• minor fixes and improvements in documentation