Changes to the haystack complexity code.
Changed the command line option for specifying how many numbers to include
Renames
Alternate case modifier now starts in random state
Added tests for pick N from M
Made an application class.
Fixed up the case modifiers towards having a common api for all modifiers
Changed how number_count is passed to the modifiers
renamed function so number injectors and case modifiers have the same api
Updated README
Changes to the code for letter substitution.