Refactored string manipulation, connecting procedure changed

Methods using strings are fixed to use `string.format()` instead of `string0 + str(data) + string1`. The latter much more error prone. Besides, `string.format()` is more readable and makes shorter, nicer code. 

----

Apart from the string manipulation a small alteration was made to the procedure of connecting to pods. Reason: separating feeding data from actual work.

This is explained in `connecting_to_pod.mdown` file in newly created `manual/` directory which had been created in order to be a place for more real-life documentation than the `docs` which are more of technical side.