fix windows path issue

[witwall]

use basename to let get_filename support both Windows and Linux path

[joseluisct]

I have an error converting some pdf files, it is:
Internal Error: File Offset wrong for ttf table (name-data), -1 expected 174
Cannot save font to C:\Users\test\AppData\Local\Temp//pdf2htmlEX-a14136/__tmp_font1.ttf

As you can see, Path contains Windows and Linux bar... It is related to this issue?

I'm using Windows last executable:

pdf2htmlEX version 0.14.6
Copyright 2012-2015 Lu Wang [email protected] and other contributors
Libraries:
poppler 0.33.0
libfontforge 20150621
cairo 1.12.18
Supported image format: png jpg svg

Thanks.