Revert "Moved columnSearch to the first table header row"

This reverts commit 4238cbc9122c2bb290b0245181fb09fd3b2a7931.

Conflicts:
	build/js/ngReactGrid.min.js
'hideDisabledCheckboxField' option for ngReactGridCheckbox
'disableCheckboxField' option for ngReactGridCheckbox can reference arbitrarily nested object field
Merge branch 'disabled-checkbox' into merged
Merge branch 'master' into merged