Assert in AutoCompletion::isAllDigits

[wqweto]

I've been dog-fooding 32-bit Unicode Debug build here and upon entering cyrillic letters an assert poped up

In call-stack the last non-runtime line was

return std::all_of(str.begin(), str.end(), ::isdigit);

Apparently you cannot use MBCS designed isdigit with wchar_t . The only other place isdigit is (mis)used is somewhere in WindowsDlg.cpp.

Both a simple fix to replace w/ _istdigit, will send PR if assigned.