Comment 45 for bug 691380

In the Bug 526221 was proposed add to the quick filter box the feature of open
a global search when press 'Enter' key. Originally in Bug 516543 I posted this
idea for TB3.0 like an enhanced to the drop-down search menu, and then to avoid
the two search and filter boxes that appear in the 3.1 betas.
Now I wrote and extension to try do this: 'Unified search'
https://addons.mozilla.org/es-ES/thunderbird/addon/187593/
Is not fully finished and need some enhancements but is usable to test some
ideas, with options to enable/disable each thing, looking for the best
solution.
When I learn more about How work at background the filter system I expect can
try to implement a button like the proposed here in a extra customizable
button, but is in the to-do list for now.