Bugzilla fixes integrated in this commit: || <https://webkit.org/b/37445> || [Qt] Regression: Google calendar edit event details gets stuck on loading || || <https://webkit.org/b/38439> || [Qt] QT_MOBILE_THEME compile time flag || || <https://webkit.org/b/37803> || Spatial Navigation: adapt the logic of {deep}findFocusableNodeInDirection to do traversal starting from Node* not Document* || || <https://webkit.org/b/36755> || [Qt] REGRESSION: Loading of external CSS and JS files over network fails in some cases || || <https://webkit.org/b/36533> || [Qt] Compilation error on Qt for Embedded Linux built with -qconfig small || || <https://webkit.org/b/38585> || Spatial Navigation: add a layout test which runs with Frame Flattening ON ||