node higher debug level desirable - common.gypi

[diegosanchez]

Because an issue with openssl Issue#4121 @bnoordhuis found useful to have a backtrace with full information.

In order to supply it I had to change level of debug of common.gypi file from -g to -g3.

Shall we add it as default configuration for common.gypi?

[Fishrock123]

@diegosanchez could you open a PR? we can probably discuss it easier like that. :)

[diegosanchez]

I thought the debug information provided by -gwasn't enough to have a full backtrace but it's. So that I wanted to change:
'cflags': [ '-g', '-O0' ], for 'cflags': [ '-g3', '-O0' ],

But it doesn't make sense.
My bad.
Lets close the issue

[evanlucas]

closing at the request of @diegosanchez.