Fix number concatenation in some error messages

Prior to this change several error message concatenations were
erroneously written as pointer arithmetic. "abc" + 123
Consolidate ResizeBuffer functions

CSV/CSV.hpp
CSV/CSVread.cpp
CSV/CSVwrite.cpp

- Change the buffer size type to streamsize from size_t.
Use the documented type for iostreams --streamsize-- and if a function
needs the value as a size_t then cast instead.

- (CSVshared_ResizeBuffer)
Consolidate CSVread::ResizeBuffer() and CSVwrite::ResizeBuffer(), which
are identical, into this function which may be called by either.

- (CSVshared_ResizeBuffer)
Add error checking so that the buffer size cannot be larger than the
maximum value for size_t. The buffer size may be cast as size_t at
any point so it cannot be larger than size_t's maximum value.
Ignore Visual Studio's auto recovery folder