Explicitly store alternative billing preference

account.billingPreference is either:
* an empty string for none
* 'address' to use alt. billing address
* 'eInvoice' to use eInvoice data
Set account.billingPreference in import

If eInvoice data exists --> eInvoice
If a billing address exists --> address
Otherwise empty.
Use account.billingPreference in proe creation

So print billing.address or eInvoice data as requested

Also, don't completely fail if there is no address, could be that an eInvoice is being used or maybe the receiving system has an address for the account.
User activation is separate from other user edits
Show username in users list
Add search filter to search by user activity flag
Users can't change their own active flag
Make more room for cert-end column
active flag is always a boolean
Rename variable
Fix role-import bug: 'admin' role -> 'root'
Merge pull request #27 from kavi-fi/store-billing-preference

Store billing preference
Make user activation element a button
Preliminary change log UI
Added more user friendly interface for change-logs
Removed obsolete functionality
Fixed commas to dots, uniform styles, formatted date and fixed falses being undefined
Merge remote-tracking branch 'origin/master' into fixes-for-user-management

Conflicts:
	server/app.js
Chain jquery operations and move final vars to upper scope
Fix user details animation by adding clearfix