Improved: specify encoding when exporting OFX
Improved: Add option to use SGML OFX headers during export (issue #43)
This helps GnuCash desktop to better detect encoding and import OFX files, especially for users of non-Latin characters
Fixes #16, #28
Modified SGML type OFX export file.
Merge pull request #46 from choni/develop

Modified SGML type OFX export file.
Closes #43