MT#4289 fix html-id with invalid symbols

When editing a customer, the helper.name contained a hash symbol (#).
This variable is used to form the id of the html element table, by
stripping spaces from it. Now we also strip the hash, because otherwise
at least jquery will fail to find this id.
MT#4289 move /contract/customer/edit to /customer/edit

So finally, there is no customer-specific stuff left in the Contract controller.