Gergely

clean up on destruction

3

Due to statically declared objects, some artifacts aren't removed from /dev/shm when the ipc::chan object is destroyed. Steps to reproduce: Attached sample code: [ipc_plain.cpp.txt](https://github.com/mutouyun/cpp-ipc/files/7277212/ipc_plain.cpp.txt) - Place breakpoint at line 35...

- added code that enables build cancellation - revised the internal states of the build object - added function to kill the build process with all its child processes. -...