Just some convenience changes

[antoniomo]

Hi!

I added some convenience changes in your library, while respecting and not touching the original code. The changes are summarized in the updated README:

In this fork we just add some conveniences to enable the usage of this as a library in python programs.

Changes include an updated .gitignore so that it ignores unpacked models, init.py file so that it can be treated as a module, added a ldig_standalone.py file with a convenient class to detect language on text and not on files.

The original c++ branch, is merged with the original master for convenience too, since it takes away nothing from the python point of view, yet adds an extra C++ version.

I was wondering if any of this is of interest to you, and in that case feel free to merge this pull request and update the README as necessary.

Thanks for the great work!