Use batch updates for HGrid#addData.

Lazy-loading lots of data is potentially very slow, since the DataView
updates after each addition. Use DataView#beginUpdate and
DataView#endUpdate for faster lazy-loading.
DRY up changes; h/t sloria.
Merge branch 'hotfix/batch-update'
Merge branch 'hotfix/batch-update' into dev
Bump version
Merge branch 'master' into dev
Merge branch 'dev' of https://github.com/centerforopenscience/hgrid into feature/loading-icon

Conflicts:
	dist/hgrid-nodeps.min.js
	dist/hgrid.min.js