qt5.inc: allow to set the package arch globally

If Qt5 (qtbase) is machine specific, then all packages depending
on qtbase will also be machine specific, because the (initial)
qtbase configuration becomes part of Qt5/qmake, thus affecting
builds of packages built against this specific version of qtbase.

Since it is not feasible to add PACKAGE_ARCH=... to each and every
recipe that is built using qmake and depends on Qt5, we introduce
a new variable, QT_PACKAGES_ARCH, that can be set by the machine
configuration as needed.

We have to be careful though to only change the architecture of the
resulting packages if we're not compiling a 'native' package.

Signed-off-by: André Draszik <andre.draszik@linaro.org>
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>
qtbase: upgrade to 5.2.0

* drop 0027-Fix-misaligned-selection-region-with-text-when-cente.patch
  resolved in upstream commit 5d8a882c11201a29475c5ea71cfb76c9de6573f5
* drop 0020-Use-BGRA-extension-in-bindTexture.patch
  resolved in upstream commit e1325cf26e146b68725cc1a0a02b274ce3dfbe5c

Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>
qtmodules: bump SRCREVs for 5.2.0 tags

* now all modules using qt5-git should be newer than any 5.1.* version

Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>
qtwebkit: Explicitly add ICU libraries to LIBS

* fails to build without this

Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>
qtbase: remove gstreamer packageconfig

Nothing in qtbase uses gstreamer so the configure option was removed on the way
to 5.2 [1]. Fixes:

| -no-gstreamer: invalid command-line switch

[1] https://qt.gitorious.org/qt/qtbase/commit/e25a4faf4a33a758a51c1b96dfdead2f1675ccd7

Signed-off-by: Andreas Müller <schnitzeltony@googlemail.com>
qtjsbackend: remove for git versions

Found in [1]:
Qt Qml is now using its own built-in Javascript engine and does not depend on
V8 anymore. As such the QtJSBackend shared library has disappeared.

[1] http://blog.qt.digia.com/blog/2013/09/30/qt-5-2-alpha-available/

Signed-off-by: Andreas Müller <schnitzeltony@googlemail.com>
qtbase: fix paths in packageconfig *.pc files

include- and lib-paths contained build-sysroot paths

Signed-off-by: Andreas Müller <schnitzeltony@googlemail.com>