Add gzip encoding by default

[peterkeung]

We should add gzip encoding by default

[ezrobot]

[dfearnley]

Should be included as part of the default +1

[ernestob]

Compression should be there by default.

👍

[carlosmauri]

Agree. we should include it. By adding this the site gets a better score at:
https://developers.google.com/speed/pagespeed/insights/
which is important in terms of SEO
👍

[andrerom]

Could someone move this over to ezplatform repo for apache and nginx? (this repo is not used anymore) _And maybe add inline recommendation on how to deal with it when using Varnish. Should we adapt the default VCL as well pherhaps? _

[peterkeung]

PR on "ezplatform" repo: ezsystems/ezplatform#251

I considered creating a separate vhost example for the legacy bridge, but it's well enough documented here: https://github.com/ezsystems/LegacyBridge/blob/master/INSTALL.md

[gggeek]

apache default config for when mod_deflate already includes a few of these. Would it not be better to only add here the missing ones? Or at least add a comment mentioning mention that