Shorten JobApplicationSubmi* class names to Submi*.
Short variable and method names, replacing "jobapplicationsub*" with "sub*".
Rename spec files to reflect the class name changes.
Rename lib files to reflect the JobApplicationSub* class name changes.

Update specs to reflect the lib file name changes.
Rename lib/jobapplications.rb to lib/applications.rb in anticipation of renaming the JobApplication* classes.
Rename JobApplication* classes to Application*.

Update specs to reflect the JobApplication* class name changes.
Rename JobApplication*-referencing methods and variables to use the shorter version.

Update specs to reflect the renamings.