(refs #34)Link conversion checks existence of accounts and issues.
Remove unused import statement.
Returns a gray image if username has not been registered.
Expand column COMMENT.ACTION to VARCHAR(20).
Add copy to clipboard clone URL
Merge pull request #39 from tanacasino/feature/copy-to-clipboard

Add copy to clipboard git clone URL
(refs #39)Small fix for copy button.
(refs #39)Remove unnecessary attribute.
Change ISSUE_COMMENT.ACTION to NOT NULL.
Change action(IssueComment) to String type.
(refs #11) Change the value to be set in the action.
(refs #11) Fix comments to display.