Pre-calculate current part count, giving a massive speed-up to stage 1.
Add SQL patch # to schema.
Add NOT NULL
Add current part count to currentparts column after adding the column.
Merge branch 'dev-stage1-changes' into dev
WARNING: IF YOU ARE RUNNING TPG, YOU MUST RUN nzedb\_runonce\tpg_fixes.php !!!!!!
Huge speed-up to stage 1 on update-releases.