ICEC: Provide better multilingual support

Current implementation of multi-language support in ICEC is limited to:

- Product strings

- Widget titles

%localize:custom_string% is replaced by the appropriate language string for key custom_string

Multi-language support should be extended to

- page titles

- titles of channels (e.g. in People widget, News widget, RSS Feed widget)

- all other text fields (e.g. in Teaser widget)

Switch of language is identified by browser language setting.

In concrete customer case, they want to implement multi-language intranet solution using ICEC. Translated content is managed in dedicated communities, one community for each language. At the moment, switch between content source is based on personalization using profile property (not browser language setting). A better product solution (streamlined with the other items which can be displayed multilingual) would be to provide the option to define content source based on identified browser language. This could be similar, in addition to the personalization feature.