Revert "Run one phase later to ensure install tools are already done"

This reverts commit a565f66740118e0e0c372d46578ed998d177d083.
fix changelog for reversion
add a test that ensures the file is added at the right phase, with the right content
go back to creating file in memory; determine installer type(s) by inspecting the plugins in use

The template is added immediately, in the FileGatherer, allowing other plugins to insert other
content if they wish, with the content finalized later, in the FileMunging
phase.

This returns all plugin operations to their proper phases, while avoiding load
order issues if the installer file(s) have not been added yet.
Update documentation
Released 1.200005