add callable validator to entity utils
Add ellipsis to long links

- Do not truncate on server, instead use CSS ellipsis
spec: one link didn't have our new class
Tests for callable validator
Merge pull request #595 from sharetribe/callable-validator

Callable validator
Merge pull request #572 from sharetribe/truncate-long-links

Add ellipsis to long links
Reversible with up and down methods
Create Transactions
Move data from conversation to transaction
Rename conversation_id to transaction_id
Booking and payment belong to transaction
Factory specs passing
Specs passing
Structure
TEMP
TEMP
A lot has changed, a lot work to do
Fix one more test
Renaming etc.
Before moving testimonials