Remove timer when calculating bory size

Calculating body size in timer make a performance issues and impact functionalities like row selection.
cannot add records to grid
Merge branch 'master' into fix-grid-errors

Conflicts:
	src/w2grid.js
remove comment.
Merge pull request #418 from khoussem/master

Remove timer when calculating body size
Fixed issue #420
duplicate cell IDs in summary, editChange handles incorrect row for editable checkbox cells
ListView:
- navigation support for keys Home/End/PgUp/PgDown';
- changed items DOM id - now include listview name
Merge pull request #421 from wolfmanx/fix-grid-errors

 duplicate cell IDs in summary, editChange handles incorrect row for editable checkbox cells
Merge pull request #422 from kyuri/upstream

ListView: navigation support for keys Home/End/PgUp/PgDown; changed items DOM id - now include listview name