Do not attempt to copy files to the "Program Files" directories
Fix a few TypeScript warnings
Merge pull request #51 from phillip-hopper/TypeScript-Cleanup

Fix a few TypeScript warnings
Provide a different message when the file has no extension
Merge pull request #55 from andrew-polk/BL512_DRTxtFileMessage

Improve message informing user that sample texts should be .txt
Merge pull request #57 from phillip-hopper/BL-634

Do not attempt to copy files to the "Program Files" directories