Enh(gridMenu): allow i18n through gridMenuTitleFilter option

Added gridMenuTitleFilter option, which allows internationalisation of column display names within the grid menu.
This option provides a function to be called against each of the column displayNames, so if your grid header
had i18n, then that same i18n can be applied to the column show/hide labels.

The function can return either a string (e.g. i18nService) or a promise (e.g. angular-translate).