Operators 'ip proto', 'ip6 proto' and 'iso proto' can also accept a number as parameter
Add examples for 'ip proto 47', 'ip6 proto 47', 'proto 47' and 'iso proto 47'
Merge pull request #90 from Igalia/fix-ip-proto

Fix ip proto
Variable 'Inf' was not declared and initialized
Create environment including variable 'ffi' and global space as parent
Create environment with functions runtime_u32, _add, _sub...