bumps clojure to 1.5.1

clojure 1.5.0 had a memory leak bug. The fact that no one has reported
any issues with riemann suggests that riemann is not effected by the
bug, but I still feel better with the patched version of 1.5.1. :)
Include custom attributes in emails & SNS notifications

Uses riemann.codec/event-keys for a list of default
attributes on an Event.  Other keys on an Event are
custom attributes and are presented separately.

* Add riemann.common/attributes, returns a sub-map
  of an Event including only custom attributes.
* Include custom Event attributes in riemann.common/body
    * Used for email and SNS notifications

Email format example:

    At Wed Jun 12 00:33:40 CEST 2013
    doghouse dogs exception (1)
    Tags: [exception]
    Attributes: {:group "ActiveDog::DogNotFound", :alert-rate "2"}

    63.5 milliseconds per request
Exclude path information from md5 checksum file.
Merge pull request #240 from asemt/exclude_pth_in_chksum_file

Exclude path information from md5 checksum file.
fixed a typo
Merge pull request #241 from mburger/master

fixed a typo in pkg/deb/riemann
Add directoy support to 'include'
Merge pull request #242 from paulgoldbaum/config-directory

Add directoy support to 'include'
Merge pull request #237 from bmabey/master

bumps to clojure 1.5.1 for memory leak patch
Merge pull request #238 from samn/attributes-in-emails

Include custom attributes in emails & SNS notifications