Updating dataset request letter

- Made changes previously made to data inventory request to reflect here too
- Changed opening from 'requesting the following public records data' to 'requesting to inspect' because inspection is free and requesting the data itself (e.g. copies) costs money
- Removed 'public' in the opening sentence, because if you request only the public data in the dataset, the agency won't have to acknowledge specific denials
- Added temporary classification to potential denial reason
Updating citations, adding additional background information
Add links, update disclaimer, add placeholder for case law citations
Clarifying wording with regard to inspection, denials
Add information about standing requests
Merge pull request #2 from webster/master

Updates to data request templates and general information