[SBT] Add some excludes kept in Scala.gitignore .

Scala.gitignore currently has more entries for SBT than SBT.gitignore itself.
Copy missing entries here.

Global/SBT.gitignore

 # Simple Build Tool
 # http://www.scala-sbt.org/release/docs/Getting-Started/Directories.html#configuring-version-control
 
+dist/*
 target/
 lib_managed/
 src_managed/
 project/boot/
+project/plugins/project/
 .history
 .cache
+.lib/