Fix post filtering via dropdown - issue #838
Allow for WP bug #23268

Ref: http://codex.wordpress.org/Class_Reference/WP_Query#Custom_Field_Parameters
Ref: http://core.trac.wordpress.org/ticket/23268
Keyword density preg_quote fix
whitespace
Submodule update
Merge pull request #841 from jrfnl/Issue-838-post-filtering

Fix post filtering via dropdown - issue #838
Merge pull request #842 from jrfnl/Double-check-meta-queries

Allow for WP bug #23268
Merge pull request #848 from jrfnl/Keyword-density-preg-fix

Keyword density preg_quote fix
Bump to version 1.5.2.3