Create codechecker.cpp

This code does following :
1. Fork child process
2. Drops privilege of child process to normal user, if it was running under root privilege
3. Sets alarm for child process and terminates it if it exceeds given allowed time limit
4. Limits data and stack resources (memory) to given Bytes
5. Makes parent process wait for child process to finish/exit
6. Compiles the c++ file provided in command line. Publish compilation failures if any
7. Executes the program if compilation is successful.
8. Report the results.