[MOD] add cartlib to TikiLib::lib

git-svn-id: file:///var/local/code.tiki.org/tikisvn/branches/12.x@49774 b456876b-0849-0410-b77d-98878d47e9d5
[REF] cart: Move most of the "add to cart" logic out of the plugin and into cartlib

git-svn-id: file:///var/local/code.tiki.org/tikisvn/branches/12.x@49775 b456876b-0849-0410-b77d-98878d47e9d5
[REF] cart: Streamline product info (no need for a separate params array)

git-svn-id: file:///var/local/code.tiki.org/tikisvn/branches/12.x@49776 b456876b-0849-0410-b77d-98878d47e9d5
[REF] cart: Move more of the input processing and logic into add_to_cart library function (autocheckout still only in plugin TODO)

git-svn-id: file:///var/local/code.tiki.org/tikisvn/branches/12.x@49777 b456876b-0849-0410-b77d-98878d47e9d5
[FIX] cart: Gift certificates handling

git-svn-id: file:///var/local/code.tiki.org/tikisvn/branches/12.x@49778 b456876b-0849-0410-b77d-98878d47e9d5
[DOC] Rebuild phpdoc @return param for TikiLib::lib function as CartLib and WizardLib were missing (phpStorm seems to like backslashes in front of the class names, hope everything else does...)

git-svn-id: file:///var/local/code.tiki.org/tikisvn/branches/12.x@49779 b456876b-0849-0410-b77d-98878d47e9d5