close MapsterMapper#235 ISet support

fix MapsterMapper#188 Mapping to inherited interface not working

fix MapsterMapper#227: EmptyCollectionIfNull, CreateNewIfNull Destina…

…tionTransform

support mapping to IDictionary, IReadOnlyDictionary

fix nested EnableNonPublicMember
fix TwoWays IncludeMember

- feature: generating dynamic proxy for interface (sp. thx to Satano)

- feature: UseDestinationValue
- feature: null propagating property path
- feature: support multiple sources
- change: introduce Mapper & deprecate Adapter
- benchmark: change to banchmark.net (sp. thx to SergerGood)

fix MapsterMapper#209 map to target with the same list

- Change project to C# 8

- Support NullableAttribute
- Improve IList performance
- Fix mapping to existing struct

package: add netstandard 2.0

feature: support code generation
feature: 2 ways mapping
feature: unflattening
feature: map to constructor
feature: map by properties path
feature: max depth
feature: add before mapping

fix: Compile using ForDestinationType

fix: include non-public member
fix: EF not support Expression.Default

fix: map to target from null value should return null

- minor performance improvement

- improve script readability
- support ExpressionDebugger