Export build.sbt values inside sbt.

* Expose the values PAST the Eval/sbt.compiler package.
* Find projects using the name API rather than finding htem and dropping all values immediately.
* Adds a test to make sure the .sbt values are discovered and set-able
* Expose .sbt values in Set command and inside BuildUnit methods.
* Ensure `consoleProject` can see build.sbt values.
* Add notes for where we can look in the build if we want to expose .sbt values between files.
Fix the val extractor to only pull sbt types rather than all.
Minor cleanups and fix Eval tests to work correctly.
Merge pull request #1456 from sbt/wip/build-sbt-vals-in-set-command

Export build.sbt values inside sbt.
Contributing updated
Merge pull request #1463 from jaceklaskowski/docs-contributing

Contributing updated
Consolidated resolution. Fixes #413

This adds a new setting key called updateOptions, which can enable
consolidated resolution for update task.
The consolidated resolution automatically generates an artificial
module descriptor based on the SHA-1 of all external dependencies.
This consolidates the Ivy resolution of identical Ivy dependency
graph across multiple subprojects.

This is how it's enabled:

    updateOptions := updateOptions.value.withConsolidatedResolution(true)
Merge pull request #1454 from sbt/wip/resolve-consolidation

Consolidated resolution
Expand ModuleReport into the full Ivy resolution report. #1200

Currently sbt's update task generates UpdateReport from
Ivy's resolution report.
For each configuration there's ConfigurationReport, which contains
just enough information on the resolved module/revision/artifact.

Speaking of module, in Ivy module means organization and name,
and organization, name, and version is called module revision.
In sbt, module revision is called Module.
This is relevant because to talk about evictions, we need
a terminology for organization and name combo.

In any case ConfigurationReport is expanded to have `details`
field, which contains Seq[ModuleDetailReport], which represents
organization and name combo plus all the modules
just like Ivy's resolution report XML.
Furthermore, ModuleReport is expanded to include licenses,
eviction, callers, etc.
Implemented general eviction warning. #1200

    a> update
    [info] Updating {file:/foo/}a...
    [info] Resolving org.fusesource.jansi#jansi;1.4 ...
    [info] Done updating.
    [warn] Some dependencies were evicted:
    [warn]  * org.scala-lang:scala-library (2.10.1) -> 2.10.3
Fixing NullPointerError caused by reading String from Ivy directly
Fixing more NullPointerError by wrapping license URL with Option
pseudo-case class VersionNumber

VersionNumber is a pseudo-case class that represents any form of
version number. The unapply extractor can parse String into
three sequences that makes up VersionNumber.
VersionNumberCompatibility trait uses two VersionNumber instances
to evaluate binary compatibility between them.
Two implementations SemVer and SecondSegment are provided.
Implements eviction warning stories. #1200

This implements all stories from https://github.com/sbt/sbt/wiki/User-Stories%3A-Conflict-Warning.
When scalaVersion is no longer effective an eviction warning will display.

    Scala version was updated by one of library dependencies:
        * org.scala-lang:scala-library:2.10.2 -> 2.10.3

When there're suspected incompatibility in directly depended Java libraries,
eviction warnings will display.

   There may be incompatibilities among your library dependencies.
   Here are some of the libraries that were evicted:
      * commons-io:commons-io:1.4 -> 2.4

When there's suspected incompatiblity in directly depended Scala libraries,
eviction warnings will display.

  There may be incompatibilities among your library dependencies.
  Here are some of the libraries that were evicted:
      * com.typesafe.akka:akka-actor_2.10:2.1.4 -> 2.3.4

This also adds 'evicted' task, which displays more detailed eviction warnings.
notes. #1200
Improve doc on ModuleDetailReport per @jsuereth
Merge pull request #1467 from sbt/wip/eviction-warning

Eviction warnings (Fixes #1200)
Improved consolidated resolution testing. #1454
Updated notes
Move one item to bug fix