BuiltinCommands.initialize has load-commands commented out
Moves JCenter and Bintray repo into object Resolver. #1405

This is more consistent with other hardcoded repos like Sonatype.
Also hardcoding everything to https.
Fixes #1181/#1501. Fixes ArrayIndexOutOfBoundsException: -1

When the compiler reports back the error to CompilationUnit created by Eval#mkUnit, it sometimes returns OffsetPosition whose `source` is set to `NoSourceFile`.

This causes ArrayIndexOutOfBoundsException. The current workaround is to pattern match on the passed in pos and create a new one when the incoming source looks suspicious.
I have not figured out whether this is caused by our macro code or compiler.
There are various build.sbt errors that would cause this behavior:

```scala
libraryDependencies ++= Seq(
  depA
  depB // missing comma
)

lazy val bob = scala.Console println

test ++

run+
```
Merge pull request #1505 from jaceklaskowski/initdetailed-help-fix

BuiltinCommands.initialize has load-commands commented out
Merge pull request #1508 from sbt/wip/jcenter-fix

Moves JCenter and Bintray repo into object Resolver. #1405
Merge pull request #1509 from sbt/fix/1501

Fixes #1181/#1501. Fixes ArrayIndexOutOfBoundsException: -1
Use HTTPS for downloading artifacts from Maven Central

Sonatype have enabled HTTPS access for Maven Central:

http://central.sonatype.org/articles/2014/Aug/03/https-support-launching-now/

Note that the Ivy class IBiblioResolver contains the old http url
(ie DEFAULT_M2_ROOT="http://repo1.maven.org/maven2/"):

http://svn.apache.org/viewvc/ant/ivy/core/trunk/src/java/org/apache/ivy/plugins/resolver/IBiblioResolver.java?revision=1557968&view=markup#l72
Update misc tests and doc to reflect HTTPS access for Maven Central
scalariform project/Docs.scala
Adds sbt.repository.secure (default: true) #1494
Fix pom-export of Maven Central repository

Commit a1e26ca6 broke the `make-pom` & `pom-advanced` dependency-management
tests by replacing one reference to `IBiblioResolver.DEFAULT_M2_ROOT` in
`Resolver`, but not the other reference in `MakePom`:

https://travis-ci.org/sbt/sbt/jobs/31939788#L2517-L2519

...the secure url was no longer recognised as the default Maven Repository
root, so was erroneously exported.