added new base class for tests, moved there cleanXML() method and created a simple test for Jira
moved addHeading() to the base class and made the headline tests for Jira markup pass
moved addHorizontalRule() to base class and made Jira horizontal ruler test passes
made multiline blockqoute test cases pass
moved processParagraph() to the base class
added paragraph test cases to JiraTest
introduced processRestOfLine() method
small refactoring, blockqoute inline test passes
added Jira emphasized text
added Jira strong text
refactoring
mixed test case passing but added commented one which is not passing
added PHPDocs
Merge branch 'public-interface' into jira

Conflicts:
	src/MarkupTranslator/Translators/Base.php
	src/MarkupTranslator/Translators/Github.php
	tests/MarkupTranslator/Translators/GithubTest.php
Merge pull request #16 from hackathoners/jira

Jira
Merge pull request #17 from hackathoners/public-interface

Public interface