prioritized task handling is disabled by default now

This could be a breaking change for someone who relied on the default value of Tasker constructor. Previously, when Tasker was instantiated without any parameter the prioritized task handling was enabled by default. Now (since v1.4) the Tasker will not enable the prioritized handling by default unless you explicitly instantiate the Tasker like this:

Taker tasker(TRUE);

You can also set the priority value at runtime by setPrioritized(bool value) and query it anytime by isPrioritized().

The goal of this change is to get rid of possible surprises that some tasks are sometimes not executed because previous tasks were running for too long - this could happen when you enabled the prioritized task handling and didn't realize how it changed the internal processing.

So for almost all users this version brings more predictable behavior and that's good (the less surprises when using a library the better).