bandwidthMax cleanup

- consistent use of "downlink speed" in place of "bandwidth"
- drop "theoretical" in "maximum downlink speed": redundant based on
  definition
pedantic fixes..
fix JSON formatting
remove trailing whitespace
rename underlying connection type

The distinction between 'connection type' and 'underlying connection
type' is subtle and easy to confuse. Moving to 'underlying connection
technology' is both more accurate and should reduce/eliminate the
confusion.
ceiling -> max in JSON data
Merge pull request #15 from igrigorik/bandwidthCeiling

bandwidthMax updates