Rename comments table to activity
DDL and code updates

- Update activity table schema to work with activity log type data
- Add records for issue being opened to the log
- Record comments to activity table
Add the activity log to the issue view
Add close records
Merge branch 'master' into activity_log
Update the sample data for the new schema
Add activity logging to the hooks
Merge branch 'master' into activity_log
Update updateComments method to new schema
Don't store empty fields
Fix add form redirect when server side validation fails
Change the category to be an extra field [DB CHANGE]
Add project handling (Fix #31) (Fix #38) [DB UPDATE]
Update sample data
Move the text for new issue descriptions to a proper template file.
Fix sample data
Fix admin disabled menu displays irrelevant content (Fix #50)
Fix extra fields validation (Ref #69)
Add support for issue relations (Ref #76) [DB UPDATE]
Add a base project class
Mostly to add type hinting and code assist.