Show DownloadDialogFragment from onResume() instead of onRequestPermi…

…ssionsResult(). (mozilla-mobile#970)

Show DownloadDialogFragment from onResume() instead of onRequestPermi…

…ssionsResult(). (mozilla-mobile#970)

Increment versionCode for potential v1.0-RC4.

Increment versionCode for potential v1.0-RC4.

Closes mozilla-mobile#774: Fix "crash" when erasing history; RC3.

Bump version code for new RC release.

Do not auto mirror "forward" button. (mozilla-mobile#744)