P&L layout

Remap FreeAgent's P&L for management reporting. Rename a category (✎), add your own sub-categories (+ Sub-category), rename/delete sub-categories, and drag accounts and sub-categories to organise them. Add account creates an app-only virtual account (no nominal code) for internal analysis - reallocate, split and stretch into it just like a real one. The four top-level groups stay fixed (only their display names change). FreeAgent is never changed.