Importing issues into existing GH projects

[mskd12]

In projects which already have PR's(E.g., https://github.com/jersey/jersey), the JIRA Issue ID to GH Issue ID mapping will be affected.
E.g, Say, there are 270 PR's in the project already. The first issue created would be "#271" instead of "#1".

This will break the following:

1. Sub-Tasks
2. Issue-Links
3. Regex used in jiraHtmlToMarkdown, will need to be changed [JERSEY-23 needs to be converted to #23(+offset)