GH-120 Documentation updates

  Minor formatting changes, specifically capitalization of r10k at the start of sentences.
  README.mkd:
    Update documentation links to reflect the changes below.
  docs/common-patterns.mkd:
    New document showing common patterns to advise users.
  docs/dynamic-environments.mkd:
    Add link to workflow-guide.mkd.
  doc/dynamic-environments/configuration.mkd:
    Move invalid_branches description to this file.
  doc/dynamic-environments/git-environments.mkd:
    Comment on ability to use subversion.
    Clarify the details of 'how it works'.
  doc/dynamic-environments/introduction.mkd:
    Update introduction to reflect environmentpath beginning with puppet v3.5.
  doc/dynamic-environments/quickstart.mkd:
    Provide alternate method to access a dynamic environment.
  doc/dynamic-environments/usage.mkd:
    Clarify how forge modules are treated.
  doc/dynamic-environments/workflow-guide.mkd:
    Completed workflow guide.
The previous document explained how dynamic environments worked but we jump ahead to use directory environment syntax; either we should yank the old dynamic environment explanation entirely and only reference directory environments, or we should explain them separately. (Alternately, we can just link to the specific documentation for master configuration).