normalizing boolean query arguments across databases

Squashed commit of the following:

commit b7ed39aac2718c3d7b7dc1ff668386edd3305d76
Author: Márcio Almada <marcio3w@gmail.com>
Date:   Tue Jan 28 21:45:09 2014 -0300

    finishing boolean value normalization
    better tests for affected filters

commit 5d459f542f3b481adbf4ef5a1c06a28096d64734
Author: Márcio Almada <marcio3w@gmail.com>
Date:   Tue Jan 28 14:27:37 2014 -0300

    trying to normalize boolean values for EQUALS filter across all databases