Update vi.po

Update translate vietnamese
[FIX] #1526 - Missing filename on binary fields download
This is an updated colombian chart of accounts:
- Accounts based on puc.com.co
- adatpations according to current law and last fiscal reform of 2013/14 incorporated (eg. INC, CREE)
- default: 6-numberd, 6th level are account, others views according to colombian PUC regulations
- default accounts predefined according to standard use case
- Most colombian taxes preloaded. Level of detail adjusted to present and future DIAN reporting requirements
- Complete Tax Code layout for generating all necesary transactional fiscal information, Taxes (INC, IVA, CREE), Retentions (ReteIVA, ReteRENTA), Autoretentions (AutoretentionRenta, CREE) - Including predefined cases for import/export, trade with free trade zones, and trade with Companies under the international trade regime
- EXCEPT: ICA Community tax not included, as differs greatly un per city level
[FIX] #1526 - Missing filename on binary fields download
Imprint corrections
Imprint corrections - typo
Merge pull request #1790 from thanhchatvn/patch-2

Update vi.po
Merge pull request #1800 from blaggacao/8.0-l10n_co

8.0-l10n_co
Merge branch '8.0' of https://github.com/odoo/odoo into 8.0-win32