adding Grunt for rpm builds updating package.json

 package.json dependencies have been updated reflecting changies in
 express toward v4 of the express api.

 In addition to that logging is now migrated to bunyan as the output of
 even a single boomerang-express server may exceed the size and IO
 threshold of any standard-sized virtual-machine fitting the requirements
 of boomerang-express.

 Therefore bunyan has been introduced to allow users to store logs in a
 central logserver (i.e. Graylog2). For an applicable workload created
 by boomerang-express this means more data can be compared and
 aggregated in order to analyse user behaviour.
Fixing URLs in README.md example to reflect HTTP/S versatility
Lots has changed and lots need context...

 # config/master.json

 - migrate definition of Numbers to a configurable field in master.json
   Boomerang.js is capable of sending a large variety of datapoints as
   strings and numbers due to "Quirks" in the way nodejs and mongodb
   handles numeric values it is advisable to filter out parameters that
   are numeric in nature and should be casted to be such during the beacon
   import state. Should a boomerang user see the need to adjust the list
   he may do so using an array in config/master.json

 # app.js

 - _Use a more advanced logging mechanic leveraging bunyan:_ Given the size
   and quantity of requests and data generated by boomerang-express it was
   necessary to have a structured logging mechanism to allow generated data
   to be moved off of the log directory of the server and into a logserver
   through an applicable protocol.

 - _Migrate from express.js v3.x to v4 API_ due to the changes in the way
   will handle middleware in the future application initialization has been
   mostly rewritten to reflect these changes.

 # lib/routes/index.js: app.any(*)

 - _split off Resource Timing data_ into its own collection (resources)
   Using the Resource Timing API in modern browsers and the "restiming.js"
   plugin in boomerang.js a beacon may also contain data referring to
   retrieval timing of other assets on a page. To ease use of these datapoints
   by analysis tools I split off datapoints referring to assets. A reference to
   their unique beacon and subsequent page load timing data is however kept.

   For more information on Resource Timing APIs the reader is asked to refer
   to the W3Cs documentation of the Resource Timing API standard:

     http://www.w3.org/TR/resource-timing/

 - _Support POST based Beacons:_ A previously overlooked case for beacon retrieval
   is the case where beacons are sent using POST-Requests as the datapoints collected
   by boomerang and plugins has exceeded the maximum number of characters in a URL.

 - _Support clicks.js plugin:_ allow handling beacons sent using clicks as they are
    different to standard beacon data sent after page.load.

 # lib/routes/index.js: mangleQuery()

 - _Anonymize IPs retrieved through beacon request-IPs:_ Due to the requirements in
   jurisdictions such as Germany hosters are required to anonymize analytics data
   so as to not pin point data to an explicit request or person for their personal
   safetys sake.
remove /boomerang-express/ directory references