Handle/explain request_timeout in elli_example_callback.
Correct path to include file.
Makes this file compilable from the erlang shell.
Use proc_lib:spawn instead of spawn for more info in crash report.
Info about the creator of this processes, sibling processes
and more info regarding the crash will be displayed.
Note: This does not affect crases in the user code, these are catched by elli.
For more info on proc_lib, look here:
http://www.erlang.org/doc/man/proc_lib.html
Merge pull request #69 from anha0825/proc_lib

spawn processes with proc_lib