Support ISO8859-1 for SAINT imports

For all non-english speaking countries you're facing the problem with non-ASCII characters like ü, é, ç, Æ, ...

Using Excel to manage campaign sheets or other SAINT files, you run into the problem that a European Excel per default saves ISO8859-1 and won't save UTF8 at all. Depending on the Excel version you might be able to save a unicode, but this also doubles the file size.

Would be great if ISO8859-1 could be supported by SAINT.

Additionally please don't accept ISO8859-1 files that have characters with charcode >127 in SAINT standard import. Those are treated as UTF-8 on the servers, but will produce unreadable characters, since ISO8859-1 != UTF-8.

Please also accept UTF-8 files with a BOM. If you use an other tool to save SAINT sheets that saves UTF with BOM, SAINT won't accept although valid UTF-8.