Converted to AutoPlugin, and prepared for next major release, inclung Bintray support.

[metasim]

Supersedes #31.

History:

• Updated SBT and plugin versions.
• Fixed initialCommands.
• Updated library versions and cleaned up imports.
• Renamed plugin and key definition files to match type names.
• Fixed overly-agressive ignore definitions. "sbt" entry hid new files in primary package.
• Improved excludes test, ensuring desired library was included and excludes were properly applied.
• Converted to AutoPlugin.
• Added Bintray support.
• Preparation for 1.1 release.
• Fixed license link.
• Bumped release version.

[jsuereth]

LGTM