[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.

[IMP]Improved code and removed access right of journal.period

[REM]Removed code related to account.period.

[FIX]Fixed traceback for company_id.

[FIX]Fixed traceback for context_today.

[FIX]Fixed traceback for context_today.

[FIX]Fixed traceback for invalid syntax for date type.

[FIX]Fixed traceback for invalid syntax for date type.

[IMP]Improved dateformt of date_account field.

[IMP]Improved dateformt of date_account field.

[REM]Removed date_account field,sum_period field.

[REM]Removed some unused code for account period and improved some code.