*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.
"Tag" might cause confusion; suggest:
Links to files will include the language name (e.g. "PDF (English), HTML (French)")
As much as I like "Klingon", someone will probably tell us to remove it later, and they'll be right :)