Data sending in debug mode

[mrfatguy]

In default implementation (#18) data measurement loop puts new measurement to the data sending loop (to be sent to the server) only if that data is different than the previous data probe's value.

In other words, as in #18, the golden rule of thumb is:

Check every PROBE seconds, send every SEND seconds, but only if data is different then previous measurement

For debug purposes, in addition to above, we need a special debug mode, in which data probes (measurements) are put to data sending loop every PROBE seconds irrespective of the fact, if it is different than previous or not.

Please, implement a checkbox in app's configuration screen that controls (enables and disables) this special debug mode.