Mention ProGuard in the JNI documentation.

Change-Id: I7822ec1eca0290eba1f4b08eca6794b41172d606
Stop using ErrorStrings for apache.

These strings only ever end up in logcat (at best), so there's no
point having them translated. Also, rename the ErrorStrings class
and move it android.webkit where the last remaining caller lives.

(congrats webview people, this is now your mess to maintain.)

Change-Id: I04dae37c34191b26a69282970318c1b782af1edf
Merge "Stop using ErrorStrings for apache."
Merge "Mention ProGuard in the JNI documentation."