Clean up DB docs - 1. Improve content flow of install experience docs

"The installation experience in the Confluence setup guide is excellent now - it's clean and logical, without too much skipping around. However, it's missing the database setup guides in step 5. The setup guides should be cleaned up (made to look professional and checked for quality/accuracy) and integrated into the main path for production installation. Some have children pages for creating a data source in Tomcat, others do not. This should be consistent. These were all made in a haphazard way years ago, even before we had a docs team. The warning at the top of the Oracle guide guide has been there for years - it was the product of an early frustrated developer, I suspect!

1. The Any External DB guide should be deprecated; it's from before we had supported platforms.
2. The parent page Database Setup Guides should be deprecated; all its children should be moved to underneath the main Confluence setup guide."

Notes:

• DB setup guides now display in-text in the updated Confluence Setup Guide page.
• Revised the text to standardize phrasing across the sections.
• Softened the Oracle DBA statement at page top. SEE:
• Included Luisa's recent change to the Database Setup For MySQL page: "Specify/Increase the value for max_allowed_packet {shell> mysqld \--max_allowed_packet=32M}
• I have added procedural panels using the panel macro to the Database setup pages. These pages contain includes and excerpts (extant), but the panel macro may make this content appear inappropriately in other pages to which it is pulled in as an include.
• The Configuring an Oracle Datasource in Apache Tomcat requires page completion and formatting – it is currently a series of placeholders headings. I was uncertain about which content to migrate from the main Oracle DB page, if at all. The text include is therefore styled to make its appearance felt as an obvious include.
• The 'Before You Start' points at the beginning of the Confluence Setup Guide are fairly rudimentary – if retained, they will require reworking.
• The updated page with all content and formatting changes is at: http://confluence.atlassian.com/display/DOC/DRAFT+-+Confluence+Setup+Guide
• Have checked the online help dependencies – there are no problems with deleting the Any External Database page. Agree that the content of this page is redundant and adds to the docs maintenance load.
• The Database Setup Guides page is redundant and should be deleted IF the DB setup guides are migrated to become children of the Database Configuration page.
• The 'configuring a dataset' child pages will need to be migrated to the parent DB Configuration page. See attached screenshot.