scrooge: Fix parsing of comments that contain parentheses
Problem

Scrooge-generator fails to parse the following:

struct MyStruct {}

This is caused by a bug in the whitespace regex (parens inside the grouping are taken literally).

Solution

Fix the regex, add tests.

RB_ID=537357
Update sbt projet definitions of (util, ostrich, scoorge, twitter-server)

Problem

In order to release our libraries for the open-source community, we need to update
the version of those.

Solution

Update the version in the sbt project definition.
While I was there, update also sbt to the latest version and increase the jvm
configuration for the code cache.

RB_ID=537603