Fixes #332, #369. Watchable totalServerItems

Thanks to @keithharvery for the PR. The `totalServerItems` grid option can
once again be set to a string, which will be watched by the grid and
reflected in the footer if updated.

Also added tests to directivesSpec.js for using a normal number and using
a string.
Adding basic test specs for i18n
Adding pt-br.js (Brazilian Portugeuse) to i18n

Fixes #371

Thanks to @dipold for the translations and pull request.