add an option to use libnatspec for code page detection (maybe even conversion) instead of using hardcoded values

[unxed]

I am talking about DeduceCodepages(). At the moment there are hardcoded conversion tables. But, in general, it would be logical to move such things related to working with locales from Wine to a separate library. libnatspec is just such a library.

Etersoft/libnatspec#3

[unxed]

This library can also be used for charset conversion instead of borrowing Wine code directly.

[elfmz]

This library can also be used for charset conversion instead of borrowing Wine code directly.

performance is the question

[unxed]

Back in the days of the iconv branch, there seemed to be some performance testing tools that showed that iconv was slower. Can you apply the same tools to libnatspec?

[elfmz]

Its possible, but whats problem with current solution, that may be fixed by using yet another library?

[unxed]

1. libnatspec has more complete code pages info I guess
2. no need to sync such info with Wine from time to time

@vitlav probably can suggest other advantages