fixes for trac #4730 (also #4748)

Modifications to 

app/controllers/geocoder_controller.rb
app/helpers/geocoder_helper.rb
test/functional/geocoder_controller_test.rb

to "Support more syntax for lon/lat coordinates". Added tests, then added code and tests to get at the requests that are more clearly spelled out in #4748 than #4730. Went beyond the request so that latlon can be cut-and-paste from Wikipedia entries (and for that I added primes and double primes to the regexps).

Have not added support for UTM requested at the bottom of #4748.