Swap out booleans in ancestors map with ints

This converts the myriad of `!0`s in the optimized code with `1`s, saving about 4kb on `reversi.js`. `ancestors` is only every used in `ClassTypeData`, and there its usages are wrapped in `!!()` so the fact that it's an int instead of a boolean is immaterial.
updated corejslib to use 1 instead of true for ancestor maps
Added java_lang_Object to its own ancestor hash
Added option 'relativeSourceMaps' to sbt plugin
Merge pull request #148 from Peluko/relative-source-maps

Added option 'relativeSourceMaps' to sbt plugin
Merge pull request #145 from lihaoyi/patch-1

Swap out booleans in ancestors map with ints
Allow setting of package directories
Merge pull request #159 from InTheNow/set-output

Allow setting of package directories
Binary Search for  java.util.Arrays
Merge pull request #162 from techaddict/java_array_bsearch2

Binary Search for  java.util.Arrays
Implemented java.util.Arrays Binary Search for Float, Double and Anyref
Merge pull request #169 from techaddict/java_lib2

Implemented java.util.Arrays Binary Search for Float, Double and Anyref
Fix #166: Correctly handle special types scala.Nothing and scala.Null

scala.Nothing and scala.Null are mapped to scala.runtime.Nothing$ and
scala.runtime.Null$ respectively by the Scala backend. This commit
adds the same behavior for the Scala.js backend.
Implemented AtomicXXX and YYYReferences in javalib, including tests
Remove exceptions duplicated in java.util and already defined in java.lang

Remove definitions for IndexOutOfBoundsException,
IllegalArgumentException and ArrayIndexOutOfBoundsException from
java.util under javalib/.

They were introduced in 'Binary Search for java.util.Arrays' (67842f2682).
Merge pull request #170 from lihaoyi/patch-2

Implemented AtomicXXX and YYYReferences in javalib, including tests
Add tests for Arrays.binarySearch range checks

Fixes a typo in the current exception messages by making the
messages more standard compliant.
Merge pull request #171 from jonas/arrays-binarysearch

Minor improvements to Arrays.binarySearch patch series
Fix #157: Add trailing $ to names returned by getClass.getName on objects
Fix #151: Corner cases for Double/Float toString