Renames Powershell screenshot

Powershell screenshot was misnamed for case-sensitive operating systems
Merge pull request #30 from waynegraham/feature/fix_image_link

Renames Powershell screenshot
Fixes typo in markdown
Fix module 5 typo

Fixes typo in module 5 (and cleans trailing whitespace)
Merge pull request #31 from waynegraham/feature/module02-typo

Fixes typo in markdown
Merge pull request #32 from waynegraham/feature/fix_module05_typo

Fix module 5 typo
Module 6 Copy Edit

Some updated prose for module 6.
Merge pull request #33 from waynegraham/feature/module06_copy_edit

Module 6 Copy Edit
copyediting of install
copyedit and minor changes to mod 9
adding framing and copyediting
adding final module with wrap up and additional resources
adding new module to sidebar
adding description for tokenizing command
removing graphing and adding it to a challenge in 12. updated 13 to reflect
fixing typos in new module 14
adding more to coaches guide
Update 2014-09-19-module13.markdown
Update 2014-09-19-module11.markdown
Update 2014-09-19-module12.markdown