Introduce wsuwp_validate_domain to enforce similar domain rules
Use wsuwp_validate_domain as part of the site creation process
Introduce wsuwp_validate_path to validate path names
Use wsuwp_validate_path when adding new sites
Domain should be lowercase before insertion
Remove some unnecessary functionality in wsuwp_validate_domain

The strtolower decision can be made elsewhere
Validate domain and path on network edit via wsuwp_validate_*
Ensure a leading slash is always on the path
Merge pull request #81 from washingtonstateuniversity/edit-network

[PR] Add validation for domains and paths when editing networks