Android: Release the surface texture when not in use

With some Android versions the preview texture is released when the
application is suspended. If we don't release the texture in our
code, the preview will be empty when the application resumes.

Task-number: QTBUG-38165

Change-Id: I72244727081d8f94ee5f6cb0ab660ca59f4bb2de
Reviewed-by: Yoann Lopes <yoann.lopes@digia.com>
Doc: Improved example documentation

-added instructions on how to run the example
 (using \include to insert a section from qtbase/doc/global/)
-updated copyright year
-removed links to Qt 4 API
-rearranged some of the sections
-created links from the example pages to Qt Multimedia
-fixed QDoc warnings related to the example pages

Task-number: QTBUG-33597
Change-Id: Id45ce5cbd40dbfa384abd7260a316f6f6837c186
Reviewed-by: Yoann Lopes <yoann.lopes@digia.com>
Reviewed-by: Sze Howe Koh <szehowe.koh@gmail.com>
Rework qmlvideofx example

Task-number: QTBUG-38121
Change-Id: If06ba6ce2c66b4d735baaeb56e004861c62ea533
Reviewed-by: Alessandro Portale <alessandro.portale@digia.com>
Bump MODULE_VERSION to 5.3.1

Change-Id: Ie88b34ee769ab3abbd0a5ab0fd8b7938475916ae
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@digia.com>
Merge remote-tracking branch 'origin/release' into stable

Change-Id: Ieb521fb1e9f297a167eea19c771cb5915c01df97
Fix documentation error

Change-Id: I98f3e35677b5e07ea35898caec3f241b045b5033
Reviewed-by: Bernd Weimer <bweimer@blackberry.com>
[QNX] Introduce env variable for default audio sink

Make it possible to change the default audio sink
via a environment variable.

Change-Id: Id0e14318fc99a896b8a41196941b758a31d23600
Reviewed-by: Sean Harmer <sean.harmer@kdab.com>