changed: get rid of CStdString in cores/DllLoader/
changed: get rid of CStdString in cores/paplayer/  REVIEW PLEASE

NOTE: Changes DVDPlayerCodec's content-type to lowercase
changed: get rid of CStdString in cores/IPlayer and children
changed: get rid of CStdString in cores/
[stdstring] get rid of CStdString in epg/
changed: get rid of CStdString in input/
[stdstring] get rid of CStdString in interfaces/Builtins.cpp|h
[stdstring] get rid of CStdString in interfaces/legacy/ and interfaces/python/

Assumption: default.py is case-sensitive, notification icons are case-sensitive.
[stdstring] get rid of CStdString in interfaces/json-rpc/
[stdstring] get rid of CStdString in interfaces/
changed: get rid of CStdString in storage/
changed: get rid of CStdString in linux/
changed: get rid of CStdString in listproviders/