#1378 Switched to using a byte array instead of ArrayBuffer for RawBuffer
#1378 Java raw parser shouldn't buffer 2GB
Rewrote RawBuffer to use a list

* The array is now lazily computed
* If the buffer ends up in a file, no intermediate byte arrays are
  created
* Also fixed a bug when reading the file back in as a byte array
Upgrade to the latest SBT milestone - 0.13.0-M4
Removed Sonatype snapshots as we are using non snapshot artifacts throughout.
Improved documentation and error handling

This ensures that things like setting null headers as reported in #1403 are easier to debug.
Updated samples with 0.13.0-M4
Merge pull request #1408 from jroper/1403-null-header

Improved documentation and error handling
Merge pull request #1378 from jroper/1378-raw-buffer

Raw BodyParser consumes too much memory.
Documentation updates for the dist task with respect to #1305
Merge pull request #1407 from huntc/sbt-013M4

sbt 0.13.0-m4