ice.rb: Update to new stable release 3.5.0

- Drop existing patches, which are mostly no longer needed.
- Rediff cpp/config/Make.rules.Darwin to accommodate new
  upstream changes.

Tested on MacOS 10.6 using g++-4.2.  If it's possible for homebrew to depend upon newer homebrew-provided compilers like GCC 4.7 or 4.8, C++11 features could also be enabled.