Added includes to properties file

The Arduino library.properties specification gives the `includes` entry:

* **includes - (available from Arduino IDE 1.6.10) (optional)** a comma separated list of files to be added to the sketch as #include <...> lines. This property is used with the "Include library" command in the Arduino IDE. If the includes property is missing, all the header files (.h) on the root source folder are included.

Adding this will prevent both Time.h and TimeLib.h from being included in the IDE with the include library menu option.

Few minor updates to the Readme.md file

Change-Id: Ia05c370e8f09b75dddf11cf2aa8b5de4c21bd45d

The current (old) description claimded that the DS1307RTC
library is part of the download bundle, which is not (no longer?)
the case. Instead pointing to following now:
https://github.com/PaulStoffregen/DS1307RTC

Change-Id: I28b0c71398e56d50de0c786e4dee97d28f408481

Update Readme.md - put code-quotes around some types/identifiers

Update Readme.md - minor text alignment

Added ESP32 Arch

Update DateStrings.cpp

fixes #133

This now compiles on ESP platform v2.4.2 and v2.5.2 on Arduino IDE 1.8.9 and 1.9.0 beta.
I've also uploaded to example to ESP8266 to double check and works fine.

Fix bad URL in library.properties

Use of incorrect case in the Arduino Playground URL resulted in a redirect to the Playground home page instead of the expected Time library page.

strcpy_P not needed for ESP8266/2.5.0-beta2 sdk

Fix error grammar in file Readme.md

Update Time.cpp

LEAP_YEAR bad macro - need in parentheses.

Update TimeLib.h

Bad macros fixed

Add TimeNTP_ENC28J60 example

corrected minor typos in readme.md

Readme converted to markdown

PR #56 Fix a mistake in examples