Rename edm:AssertType to edm:Cast and clarify behavior of edm:Cast and cast()

Rename edm:AssertType to edm:Cast Define cast rules: cast primitive to string by using the literal representation used in payloads, and WKT for Geo types, fail if MaxLength is not sufficient cast numeric primitives to each other with appropriate rounding, fail if integer part doesn't fit into target type cast datetimeoffset, duration, or timeofday values to same type independent of precision cast entities and complex type instances to derived type, fail if derived type adds non-nullable properties without default value cast entities and complex type instances into arbitrary entity type or complex type by assigning values of identically named properties and casting them recursively, fail if non-nullable properties without default value remain without value cast collections entry by entry If the cast fails, the result of the cast expression is null. Make edm:Cast optional for primitive values (first three rules). Provide a more informative example, see description The same rules apply to the cast() function in URL expressions. To increase consistency the edm:IsType expression could be renamed to edm:IsOf as it resembles the isof() function in URL expressions. Accepted: https://www.oasis-open.org/committees/download.php/49125/odata-meeting-36_on-20130509-minutes.html#odata-365

https://www.oasis-open.org/committees/download.php/49203/odata-v4.0-wd02-part3-csdl-2013-05-16.docx https://tools.oasis-open.org/version-control/browse/wsvn/odata/trunk/spec/schemas/edm.xsd?rev=297 https://tools.oasis-open.org/version-control/browse/wsvn/odata/trunk/spec/schemas/edm.xsd?rev=296 Accepted: https://www.oasis-open.org/committees/download.php/49557/odata-meeting-41_on-20130613_14-F2F-minutes.html#odata-365