1) Used `const char *` instead of `char *` where appropriate, including the need to create a dummy blank string for us in certain places.
2) Set initialization of WiFiClient to 0 instead of NULL, since WiFiClient is not a pointer (probably don't need to set it to anything since WiFiClient overrides the boolean operator anyway).
3) Cleaned up some of the messaging and logic when WiFi tries to connect so that users know to wait a bit.
4) Only remaining warning messages are for casting SpanService to (void *), which I think i unavailable (and is not forbidden).
To Do: Go through examples and check for warnings (will likely need to convert `char *` to `const char *` in many places.
User can specifiy a REQUIRED minimum version on the HomeSpan Library for the sketch to compile. If the library version is older, the pre-processor will halt the compilation with a #error output
RFControl::phase() allows you to add either a HIGH or LOW entry (i.e. a single phase of a pulse. RFControl::add() continues to add a full HIGH/LOW pulse so these changes are fully backwards compatible.
Made Characteristic::PositionState **optional** for Service::WindowCovering. This appears to be a bug/exception in HAP-R2. Need to reflect this in on-line docs.
* if Accessory ID is NOT specified, the default is aid=1+aid of last Accessory, with aid of very first Accessory always set to 1.
* aid of first Accessory must ALWAYS be set to 1 - if user over-rides with another value, error will be thrown
* validation now includes checking for duplicate aids, as well as ensuring the first Accessory is always aid=1
If not specified, "aid" defaults to an index number representing the order in which the Accessories were created. Values are stored as uint32_t (which is more limited than HAP requirements of uint64_t, but makes the code easier).
TO DO: Must add validation to ensure duplicate aid values are not used.
HomeSpan