Added test app for NativeText extension

(cherry picked from commit 31b22c85a8de9e723241ba7edf325d1d77b05c19)
Added iPhone native text field POC

(cherry picked from commit f2d914b5db9706dde8bee415988b06b253c72f64)
Improved nativetext test harness

(cherry picked from commit 47c9394e7541b1e18c1749faeb236ffd5fb1f1e3)
Added new tests

(cherry picked from commit d49bf58d5a9b465a715e2918c86f275744817f1e)
Added focus tests for nativetextfield

(cherry picked from commit e6f356b4abc3eedd86e798b496ab4d84d853560b)
Updated tests for nativetext

(cherry picked from commit b46df7f0bd68586f0bc7a5974ff6839dc4b61118)
Updated README.md

(cherry picked from commit ea67d0375aee41d1410821d75411c826d86fe8ae)
Fixed broken paths