Re-add javascript code settings "slicerappstore.(os|arch|revision|release)" variables

This is required to ensure that the combox box value are consider when
first loading the page.

This partially reverts commit 433c0f6289856346a0f4aeac7afc43ced9128778.
Merge pull request #34 from jcfr/fix-regular-layout-filter

Re-add javascript code settings "slicerappstore.(os|arch|revision|releas...