Fix template strings in filter class __repr__ methods

[KlaasH]

While trying to debug an encoding problem in Cicero, I ended up digging into OMGeo again, and in the process discovered that just trying to examine the geocoder settings caused an error from postprocessors.py:

TypeError: not enough arguments for format string

Looks like the AttrListIncludes and AttrListExcludes filter classes were based off similar ones that had one additional parameter.

So this fixes that, and also:

• Changes .decode() calls to explicitly specify "utf-8" rather than rely on the default, which could potentially cause problems, as noted by @ddohler on PR #61
• Adds a non-ASCII character to the test address in the CancelIfRegexInAttr tests, since it's easier for problems to slip through the cracks if all the strings are ASCII-compatible.

None of this is urgent--the Cicero issue turned out not to implicate this package after all--but it might as well go in.

Testing

• In a Python shell, run:

  from omgeo.postprocessors import AttrListExcludes
  AttrListExcludes(["foo"], "bar")

  With these changes it will print <AttrListExcludes: bar in ['foo']>. Without, it will crash.

• ./test.sh should succeed as before.
• I don't know of a way to test the explicit decode argument. As noted in the linked comment, we didn't manage to actually get something to break because of the default encoding.

[flibbertigibbet]

@KlaasH should we close this?