added command to list all open pull requests of an organization
Merge pull request #1 from dsager/github-org-pull-requests

added command to list all open pull requests of an organization
aggregated multiple messages in a multi-line string, brought messages in line
Merge branch 'github-org-pull-requests'
updated usage
changed command for pulls of organizations to "org-pulls", added optional parameter for organization
Merge pull request #1112 from Devex/master

added command to list all open pull requests of an organization