bumping for v0.7.2 patch release

Let's see if travis will upload a release to npm for us.
Added IDEA project files to .gitignore
Removed unused variable
Fix `prefixStats` global variable leaking

`prefixStats` is leaked through stats.js and was in global scope of event emitter without failing graphite backend by pure accident.
Now it is read from config.
Removed unused parameter
fix typo in Gauges section
Convert listen server to loadable module, defaulting to udp
Add tcp loadable server module
Represent remote address in tcp server rinfo, not local
Rename server init to 'start' to reflect reality
Add basic test for each of udp and tcp server module
Update docs and example config to reflect new tcp server option
Add brief docs around server callback function sig
Add servers directory to debian package
Stat key name sanitization is now configurable at the top-level.

Setting keyNameSanitize to false pushes the requirement of sanitizing
key names to the backends. This permits backends that have less strict
character set requirements to take advantage of an expanded stat name
character set. The default behavior remains the same as collisions in
key name space are not handled if two different stat names map to the
same sanitized key name.
merge from PR155
Merge branch 'pr_155_take2' of https://github.com/shaylang/statsd into pr_155_take2

Conflicts:
	stats.js