Initial commit
work still in progress
#1572 - Fixed columns rows should now have the same height as the appropriate non-fixed rows
#1572 - added clientHeight wrapper to handsontable.dom
#1572 - Work in progress
#1572 - Modifications in fixed rows/cols + different mark-as-oversized mechanism
Merge branch 'feature/issue-1572' into merge

Conflicts:
	src/3rdparty/walkontable/src/abstractFilter.js
	src/3rdparty/walkontable/test/jasmine/spec/rowFilter.spec.js
	src/css/jquery.handsontable.css
	test/jasmine/spec/Core_viewSpec.js
#1572 - .fixedCount occurrences removed, fixed z-index for resize handlers + fixed textarea autoresize
Revert "#1572 - .fixedCount occurrences removed, fixed z-index for resize handlers + fixed textarea autoresize"

This reverts commit ae9f7c2f3f5999fada7057eb45228171f2c3d580.
Revert "Revert "#1572 - .fixedCount occurrences removed, fixed z-index for resize handlers + fixed textarea autoresize""

This reverts commit b3f74c8e68d59adda02046172d6947233aa7e169.
#1572 - Small fix for rowFilter initialization
performance improvement on callbacks demo
Merge branch 'feature/issue-1572-merged' into develop