Insteon_Thermo_i2: Remove Complex Code Creating Child Objects

The code is just too difficult to try and make work.  Either the child objects have to be stored in a hash, which results in awful looking veriable names that are not user friendly to the basic user.

The removed code made user friendly variable names, but these variables could not be used in other user code because the init code was not eval'd until runtime.
Insteon_thermo_i2: Remove Parent_Event Routine

Not needed without tied children.
Insteon_thermo_i2: Change Name of Child Objects

While designed for i2 devices, the child objects should work with i1 devices as well, except the humidity object which I don't believe exits for i1 devices.
Insteon_thermo_it: Cleanup Example Thermostat Code File

Fix to match current code base
Insteon_thermo_i2: Add Example to Thermostat Code File for Child Objects

Add example entry into code file to demonstrate how to create child objects that are tied to parent item