Added muscle picker
Numerous Changes

1) Merged Dom's changes (standardizing back/next buttons, eliminating Login Screen, renaming WorkoutTypeActivity to Main Activity)
2) Merged Troy's changes (Exercise Checklist, toggle functionality)
3) Added more columns to Exercise Checklist table, ensuring compliance with UI Design
Parcelable Activity Data Transfer Proof of Concept
Data transfer through intent bundle and sharedPreferences Added

Mostly proof of concept with console output. See comments for some
additional info
Create .gitignore

Added ignore support for .git files. Hopefully this works.