i2util 1.2 (new formula)

This is a dependency for owamp-3.4 and bwctl

Note: i2util includes binaries "aespasswd" and "pfstore" which were
previously in owamp-3.3, and therefore will generate link conflicts
with that package (but not when you install owamp-3.4, in separate ticket)
Can a test be added to do something more substantial than e.g. `--version` or `--help`? See `cmake.rb` for an example of an application formula with a good test and `tinyxml2.rb` for an example of a library formula with a good test. Thanks!