gzip: also auto-enable by default for IPRO
- Contains a change to make sure this works when both pagespeed on and
  IPRO is enabled for the same location
- This fixes a tests that fails now that we are on trunk-tracking
Style fixes
- Pointer declarations: char *c -> char* c (cpplint wont catch this))
- Space between parameters --eg: arg1, arg2
- Utilize 80 cols in comments (cpplint won't catch this)
merge oschaaf-review-keesspoelstra-gzip-enable-trunk