#13 Fixes an error in compiling on 64 bit systems

[Roberto Esposito]

in dtconf.h declaration of longToString it is mentioned "ODBCXX_PERCENT_SIGN" which is not defined anywhere. On systems that do not define "PRId64", the interested part of the code is filtered out by the preprocessor. Otherwise, a compilation error occurs. The patch substitutes the missing symbol with "%" (the percent symbol is used throughout the code without using the macro, so I felt it was safe to use it in this place as well).

[Roberto Esposito]

src/dtconv.h patch file