[IMP] account : Improved the code and also removed unwanted code.
[REM]Removed account.period object and related stuff.

[REM]Removed stuff related to account.period from every where.

[IMP]changed period_date in to date_account.

[REM]Replaced period_id with date_account from reports and imporoved stuff.

[IMP]Improved some code for account.period is now removed.