Identity and permission updates

[gdbarron]

• Identity format validation fix, #126. Thanks @DadsVacayShorts!
• Add Get-TppIdentity to retrieve Identity info given an id
• Add Remove-TppPermission, accepts output from Get-TppPermission
• Add Path param to Set-TppPermission in addition to guid
• Get-TppPermission now accepts TppObject, eg. from Find-TppObject
• Set-TppPermission now accepts output from Get-TppPermission for the object and IdentityId so you only need to specify Permission. No need to get guid and identity manually to pass in.
• Find-TppIdentity output standardized so you can now pipe to permission functions
• Get-TppPermission returns additional object and identity info
• Centralize format validation for identities
• Update help links referring to versions no longer available
• Find-TppIdentity -Me to be deprecated for Get-TppIdentity -Me
• Add option to Get-TppObject for guid
• Standardized on Id/IdentityId for the identity across all identity and permission functions
• Force missing slash retry to status codes of only 307 and 401
• Better error handling and messaging through the permission functions