First commit
Template files may be automatically set using the environment variable TRAC_CMD_TEMPLATE_FILE
Set the attribute by default before updating them with the parsing of the command line. It might prove useful when the defaut value will change.
Fix the ticket_clone and ticket_son_create command by giving the reporter in the command line and using ticket_get instead of get
The edit_comment function may now be given a prefix
If the comment is empty, abort the edition
The edit function now dumps as utf-8 and parses as utf-8
Rename query_ticket into ticket_query and add the ticket_sibling_create command.

The ticket_query command now assert if an empty argument is given
Addition of the commands ticket_accept, milestone_edit, milestone_list,  ticket_remaining_time and
ticket_remaining_time_sum.

Also add aliases to have commands like list_milestones and milestone_list
Template commands use the default template file
The ticket_sons command uses the ticket_sons method of trhaelppyercthon
Verbatim commands now use pprint
Update the documentation