Bug 991111 - Middle clicks on tiles are not counted [r=adw]
Move the click listener to the xul window to correctly get the click event to filter for site-related clicks.

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extra : rebase_source : 3fd8b2c658a695fbc9aa79d09f461acaeef2078f
Bug 991210 - [new tab page] Tiles are sometimes arranged all in a single line (wrapping as appropriate, e.g. to two lines with 5 items and then 4 items), instead of 3x3 grid [r=adw]
Always Grid_init before "load", defer size calculation to "load", and only wait for links cache for site rendering. Clean up timers triggered from previous tests to avoid unexpected updates.

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extra : rebase_source : aba79dc12fd3660c50d8004197a6b2f5a23419cb