Add replace and deleteCharAt methods to StringBuilder and StringBuffer
Merge pull request #1205 from l15k4/replace-deleteCharAt-StringBuilder

Add replace and deleteCharAt methods to StringBuilder and StringBuffer
Fix #1207: Good toString for OptimizerOptions
Merge pull request #1209 from gzm0/optimizer-options-tostring

Fix #1207: Good toString for OptimizerOptions
Use a Traverser in JSASTTest instead of a Transformer.
Using a Transformer in scalajsp is overkill.

It only needs to transform the top-level node, so a simple
function is enough.
Refactor Transformer with a single method transform().

Instead of overriding transformStat() and transformExpr(),
subclasses should now override transform(). This method takes
a boolean parameter telling whether it's used in statement
position.

Additionally, transformations of ClassDefs and their defs is
moved in a separate subclass ClassTransformer. This is actually
not used at all in our current codebase, but other people could
come up with use cases.
Merge pull request #1203 from sjrd/refactorings

Refactorings
Fix #1206: Update to sbt 0.13.6

Also fix the sbt version for the sbt-plugin-test build.
Merge pull request #1213 from gzm0/sbt-0.13.6

Fix #1206: Update to sbt 0.13.6
Fix #1208: toString for Semantics and CheckedBehaviors

Looks like this:

    Semantics(
      CheckedBehaviors(
        asInstanceOfs = Unchecked
      ),
      strictFloats = false
    )
Fix #1212: Run CI against Java 1.{6-8}
Merge pull request #1220 from gzm0/sem-tostring

Fix #1208: toString for Semantics and CheckedBehaviors
Buglist partests arrayclone-{old,new} and issue192.

They're broken on master.
Merge pull request #1221 from gzm0/cross-jdk

Fix #1212: Run CI against Java 1.{6-8}
Merge pull request #1223 from sjrd/buglist-broken-partests

Buglist partests arrayclone-{old,new} and issue192.
Fix #1222: The optimizer breaks Array.clone().
Blacklist run/issue192.scala because it relies on strict floats.
Merge pull request #1225 from sjrd/fix-reachability-array-clone

Fix broken partests
Fix #1228: Increase partest build timeout to 10h