Bug 14982: Remove C4::Dates from guided report wizard and dictionary

Bug 14982: Remove C4::Dates from guided report wizard and dictionary

This patch removes C4::Dates from files:
- reports/guided_reports.pl
- reports/dictionary.pl
- C4/Reports/Guided.pm

To test:
- Go to Home > Reports > Guided reports wizard
- Then go to 'View Dictionary' (menue at teh left)
- Click 'New definition' and step through
- In step 2. select e.g. borrowers
- In step 3 select a date field
- In step 4, select date range and test start / end dates
- In step 5, verify that dates display properly
- Save and verify that dates are insertet properly in sql definition

- Go back to Home > Reports > Guided reports wizard
- Step through the wizard and verify that it works as before.

http://bugs.koha-community.org/show_bug.cgi?id=14982
Signed-off-by: Josef Moravec <josef.moravec@gmail.com>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>