Merge pull request #41 from drupal-composer/prep-2.0-rc1

Prep for 2.0.0 RC1.

Merge pull request #30 from uWaterloo/fopen-append

Use append-only mode in fopen()

Merge pull request #19 from drupal-composer/18-rollback

Don't run rollback if missing .info files.

Fix links in changelog.

Fix links in changelog.

Merge pull request #4 from drupal-composer/03-version-info

Skip modules that already have version info.