Smaller lzo indexes: make #43 apply to current codebase

Make smaller lzo indexes by encoding the offsets instead of just writing them down naively.

Note this does not address any of @rangadi's comments from 2 years ago on #43, this is just bringing the PR up to a point where it can be applied to the mavenized build.
This is why your build failed. The maven antrun plugin is required for building the native binaries, and since the plugin was removed the native binaries were not generated, thus the errors.

Curious, is it necessary to make this change? If so, why?