Use Buffer.byteLength instead of string length for Content-Length header

This prevents Content-Length mismatches when sending multi-byte characters.

See https://groups.google.com/forum/?fromgroups=#!topic/nodejs/LAxACfj5_KI.
Merge pull request #213 from joshisa/master

Use Buffer.byteLength instead of string length for Content-Length header
Updating statusCode checks to accept all valid 2xx and 3xx HTTP status codes
Changed == to === when checking against null
Fix regression on populate fixtures
update intervalBuilder to fix regression on status in hourly stats for checks
Fix availability error
Fix regression on aggregated data
Merge pull request #228 from davidrautert/master

Accept all 2xx and 3xx HTTP status codes as successful
Add ability to define host in a single config setting
Merge pull request #239 from fzaninotto/server_host

Add ability to define host in a single config setting
Merge pull request #236 from fzaninotto/regression_populate_fixtures

[RFR] Fix regression on populate fixtures
Start fixing IntervalBuilderTests
Fix interval calculation