Fix for PUB-200

Internal pretty printer guessing type of column based on first chunk.
However, for a float column and non-float first chunk, guesser return
bad formatting string.
Minor fixes in Shalala building

- Increased Xmx for 'sbt run'.
- Removed package.scala since Scalac does not like it
Merge branch 'master' of github.com:0xdata/h2o