Please cherry-pick:

Please cherry-pick:
- created validator for company's short name (BasicData entity)
- renamed email-address validator for branch office according to naming-convention
- removed "id" attribute from everywhere where it is not explicitly needed
- changed some single-line tags to multi-lines for better readability
- added companyShortName to view and backing bean
- it is now the default instead of companyName which is now fully optional
- also added method isCompanyShortNameUsed() to interface

Signed-off-by: Roland Häder <roland@mxchange.org>