C++ Debug Guide

[CMurtagh-LGTM]

Add to guides a guide on debugging C++.

• GDB
• • Running
• • Backtrace
• • Frame
• • Printing locals and arguments
• • Passing signals
• ASAN
• • Interpretaiton of results
• • Use with gdb.
• Valgrind

https://www.youtube.com/watch?v=sLpEetN3lnk
http://users.ece.utexas.edu/~adnan/gdb-refcard.pdf
https://github.com/google/sanitizers/wiki/AddressSanitizerAndDebugger

[Bidski]

SignalCatcher and pure_evil should probably be included in this guide