Fix issue 6064: Inline images don't display on KitKat

Eliminate the invocation of
WebSettings.setBlockNetworkImage(boolean flag),
thus maintaining the the default setting of "false".

On Android versions prior to KitKat, this setting has no
effect on inline image attachments loaded with content:
URIs.  Such images would load regardless.

With KitKat, this setting does have an effect -- a
setting of "true" will block image attachments loaded
with content: URIs.

By removing this call, K-9 Mail behaves the same on KitKat
as on earlier Android versions, and the behavior on earlier
versions is unchanged.
first pass at a changelog for 4.900
bump version to 4.900
Bumped manifest to 4.900
Bumped manifest to 4.900
Bumped manifest to 4.900
Disable pull-to-refresh when remote search is not allowed

Fixed issue 6151
Restore instance state in correct order

Fixes issue 5968
Support extras for ACTION_VIEW + mailto: URI

Support the extras documented for ACTION_SEND to be used with
ACTION_VIEW to support another app that doesn't care, namely Twitter.
Alternative fix for issue 5697 - ASUS display bug
Don't crash when startActivity() fails

Fixes issue 6201
Change message body font size with slider, using new setTextZoom() WebView API, from 40% to 250%
Fix display error in account settings

* correctly initialize summary of 'Server search limit'.
* don't persist value in shared preferences
Save/restore slider state
Merge pull request #448

Change message body font size with slider
Updated Japanese translation. catch up with 4955e34.
Updated Japanese translation of the changelog.