Missing end-of-file marker

[AlexMax]

According to the Data File Header Structure for the dBASE Version 7 Table File:

The end of the file is marked by a single byte, with the end-of-file marker, an OEM code page character value of 26 (0x1A).

I do not notice this marker on any files I generate with the program, and a search for 0x1a, 1a or 26 in this library does not reveal anything that actually writes this marker.

Strangely, most programs I use to open these files don't seem to mind, but it seems like it's better to be safe than sorry.

[gam6itko]

fixed in #92