[stdstring] switch StringUtils::SplitString to StringUtils::Split
[stdstring] drop StringUtils::SplitString
[tests] add StringUtils::Split test for empty string split
[stdstring] switch CUtil::SplitParams/SplitExecFunction to use vector<string> rather than vector<CStdString>
[stdstring] switch CApplicationMessenger to vector<string> rather than vector<CStdString>
[stdstring] drop CStdString from CGUIMessage
[stdstring] switch vectors of regexps to vector<string>
[stdstring] drop vector<CStdString> from the infomanager
[stdstring] drops vector<CStdString> from CScraper
[stdstring] move CMediaSource::vecPaths to vector<string>
REVIEW [stdstring] drop use of CStdStringArray, Get/ReleaseBuffer from Edl.cpp
[stdstring] drop CStdStringArray
[stdstring] drops StringUtils::JoinString