*9037* Show titles in TOC as configured in manager/languages

A very few modifications in core to get more control about how language is shown in TOC in multilang journals.
The aim of the modifications was commented here:
http://pkp.sfu.ca/support/forum/viewtopic.php?f=9&t=13021&p=49967
The new feature also requires modifications submitted to "lib-pkp" submodule.

A deep review of the code (and specially of the literals in locale/en_US/manager.xml) is encouraged.
(Of course, they're used in the OJS pull request. I see them now.)

The division of code between PKP library and OJS needs a little work -- nothing journal-related should exist in the lib-pkp repository, for example, since it's supposed to be generalized.