Small bug fix and code cleanup in Project admin.

BB-1184
Add budget total to ProjectPlan admin.

BB-1184
Add local formatted amount to inline with amount / currency.

Also:

* Small model adjustment to ProjectBudgetLine.

BB-1184 #resolve
Use local formatted amount for ProjectBudgetLine display.

BB-1184
PEP8
Fix padding issue with tabular inline admin.
Merge pull request #805 from benkonrath/budgetline-admin-tweaks

Budgetline admin tweaks