Add info about css user-modify and -webkit-user-modify:read-write-plaintext-only

[nonmanifold]

said property often used to disable annoying input overlays in android's browsers and webViews prior to Android 4.1
However, there is at least one issue:
setting for -webkit-user-modify: read-write or read-write-plaintext-only;
causes input fields to loose some taps and harder to gain focus on older androids like 4.0.x