[doc] Added some documentaion for how to debug the LG client

client/DEBUGGING

@@ -0,0 +1,32 @@
+= Debugging the Looking Glass Client
+
+If you are asked to provide debugging information to resolve an issue please
+follow the following procedure.
+
+== If you're experiencing a crash:
+
+Run the program under the `gdb` debugger (you may need to install gdb), for
+example:
+
+    gdb ./looking-glass-client
+
+If you need to set any arguments, do so now by running `set args ARGS`, for
+example:
+
+    set args -F -k
+
+Now start the program by typing `r`. When the application crashes you will be
+dumped back into the debugger, the application may appear to be frozen. Run
+the following command:
+
+    thread apply all bt
+
+Once you have this information please pastebin the log from looking-glass as
+well as the information resulting from this command.
+
+== If you're experencing high CPU load and/or poor performance.
+
+The steps here are identical to the above, except instead of waiting for the
+program to crash, in the debugger press `CTRL+C` while the program is
+exhibiting the problem, then run `thread apply all bt` and pastebin your log
+and the results of the command.