import contacts from CSV: sanitise / cleanup non-breaking spaces from records

Importing contacts from CSV would benefit from basic clean-up and sanitation such as removing spaces from the beginnings and ends of the records.

Lack of this feature complicates importing contacts: I select file, set options, match fields and continue to next step where I get Import_Errors.csv with list of records that did not pass validation (emails, URLs, countries, etc.). After correcting those trivial problems manually I have to restart import from step 1.

Automatic removing of leading and trailing spaces would also prevent CiviCRM from importing organisation names beginning with spaces.