Merge pull request #155 from LFDM/events

Events and issues
Extracts option methods in List
First rough implementation of a find command
Attempt at an output string for find

Fix and move to formatter later
Handles error when no keyword is given
Renames option extraction in list
Help handling in Find
Splits label inclusion and exclusion extractors
Handles pagination, pr and repo options.
Extracts label exclusion in List
Adds label exclusion handling in Find
Adds more flexibility to format_issues_header

... in Formatting
Adds compatibilty of Find to Formatting
Adds query string to format_issues_header
More method extractions in List
Extracts output method in List
Adds verbose output to Find
Adds assignment, creator etc options in Find
Refactors usage screen in List and Find
Add query in global search in format_issues_header