Pass the field values through .strip() before translating them.

This fixes #17 but may require some modification of translations
which rely on the spaces being there.

For example, a translation which did a check like

    if attrs['foo'] == '     bar  ':

will now need to do it as

    if attrs['foo'] == 'bar':

Checks of this type were unreliable anyways as they relied
on the spaces which only happened with some file formats. One
backwards compatible way to do the check that works is

    if attrs['foo'].strip() == 'bar':

This has the additional cost of calling strip() twice
Update the copyright line, which I forgot to do in the last commit
Add a file about committing
propagate translator function exceptions

The existing code tacitly uses the default translator
functions if a user-specified translator throws an
exception.  Propagate this exception instead so that
translator coders can know about them.
make Relation.replacejwithi operate on geometry like everyone else

While there is only one example of replacejwithi being called, it
is clear that the arguments are meant to be type Geometry, not
(Geometry, role) tuple.  So when replacing j with i, preserve the
existing role.
Add mergeWayPoints() to remove duplicate nodes from ways. Typo fix.
typo in error message
Add copyright
Add testcase for mergeWayPoints()
Update testcases with duplicate points text
Merge branch 'duplicates'
Merge remote-tracking branch 'ual/for_pnorman'