Modified warning switches to match settings in .dproj file:
* Switched on "Explicit string cast with potential data loss", "Widening given AnsiChar constant to WideChar lost information" and "Widening given AnsiString constant lost information" warnings.
* Switched off "Platform symbol" warning.
* Removed switches that switched off "Unsafe code", "Unsafe type" and "Unsafe typecast" warnings since these are off by default in Delphi 2010.
