EML 0.2.0

• Added a configuration file infrastructure, allowing the user to
  configure sampling rates, set up non-discoverable devices and disable
  drivers at runtime. This adds a dependency on libconfuse. Please
  refer to the documentation for details.

• Added basic support for Schleifenbauer PDU power readings over the
  socket API (http://schleifenbauer.eu/downloads/API/).

  PDUs are not autodetected and should added in the sb_pdu section of
  the configuration file, as in the following example:

  sb_pdu {
    device testpdu {
      host = 10.0.0.3
      port = 7783
      rc4key = mykey # up to 16 chars, or exactly 32 hex digits
    }
  }
  

  Compiling this driver adds a dependency on libcrypto (used for RC4).

• Fixed a severe bug that lost data from long-running measurements.