CString made AppendToBuffer public, CDictionary added GetByIndex

GetByIndex can be used for loops, AppendToBuffer to append a char* to
the existing buffer, because + looks confusing in some occasions.
Undo of AppendToBuffer, not needeed.
Merge pull request #1 from Bromvlieg/master

Added function "GetByIndex" to CDictionary, which can be used for value iterating.