Merge branch 'develop-olympus' into develop

* develop-olympus:
  [develop-olympus] Increment version number to 3.0.13-dev.
  [develop-olympus] Add changelog for 3.0.12 release.
  [develop-olympus] Bump version numbers for 3.0.12-RC1 release.
  [develop-olympus] Bumping version numbers to final for 3.0.12 releases.

Conflicts:
	build/build.xml
	phpBB/docs/INSTALL.html
	phpBB/includes/constants.php
	phpBB/install/convertors/convert_phpbb20.php
	phpBB/install/database_update.php
	phpBB/install/schemas/schema_data.sql
	phpBB/styles/prosilver/imageset/imageset.cfg
	phpBB/styles/prosilver/style.cfg
	phpBB/styles/prosilver/template/template.cfg
	phpBB/styles/prosilver/theme/theme.cfg
	phpBB/styles/subsilver2/imageset/imageset.cfg
	phpBB/styles/subsilver2/style.cfg
	phpBB/styles/subsilver2/template/template.cfg
	phpBB/styles/subsilver2/theme/theme.cfg