fixes scaladoc cache not detecting -doc-root-content. #837

adds fileInputOptions key to track options that may invalidate the
cache for doc task.
Merge pull request #837 from xuwei-k/fix-scaladoc-cache-bug

fixes scaladoc cache not detecting -doc-root-content
Docs: last updates to getting started guide for 0.13.0
update url for publishing to typesafe repository
macros only require scala-reflect, not scala-compiler
add sbt-about-plugins

add sbt-about-plugins
refactored case-match in ConfigurationParser.getRepositories
Additional options for Ivy resolvers.

Specify an Ivy resolver with ", descriptorOptional" to make Ivy
descriptor files optional for that repository or with
", skipConsistencyCheck" to disable Ivy consistency checks for
that repository.
Add factory methods to PatternsBasedRepository

This commit adds convenience methods to PatternsBasedRepository that
produce a copy of the repository with metadata optional or with
consistency checking disabled.
Docs: pass build values to sphinx/conf.py via environment variables to reduce duplication.
Docs: Add cleanupCommands to howto
Docs: remove stray line in Howto/scala
Docs: Add scaladoc/javadoc howto
Docs: fix problem with title being hidden
Add documentation for how to publish to bintray and link packages online.
Merge pull request #858 from sbt/wip/bintray-plugin-instructions

Add documentation for how to publish to bintray and link packages online...
Merge remote-tracking branch 'sbt/0.13' into name-hashing