Squashed 'cwltool/schemas/' changes from 0fbe804..3c40bd3

3c40bd3 Merge pull request #250 from common-workflow-language/draft-4-to-v1.0
b4de02d clarify cwlVersion requirement
fad8810 move draft-4 to v1.0 directory
9b4e54f change cwl:v1.0.dev4 to v1.0.dev4 (no prefix)
ff05189 change draft-4.dev3 to v1.0.dev4
ce19b18 Merge pull request #249 from StarvingMarvin/master
b1482c0 Sentence about type definition simplification
REVERT: 0fbe804 clarify cwlVersion requirement
REVERT: 2acecf5 move draft-4 to v1.0 directory
REVERT: b29edd8 change cwl:v1.0.dev4 to v1.0.dev4 (no prefix)
REVERT: 9173ed7 change draft-4.dev3 to v1.0.dev4

git-subtree-dir: cwltool/schemas
git-subtree-split: 3c40bd3

Author: mr-c

v1.0/concepts.md

@@ -108,6 +108,10 @@ An implementation must resolve [$import](SchemaSalad.html#Import) and
 [$include](SchemaSalad.html#Import) directives as described in the
 [Schema Salad specification](SchemaSalad.html).
 
+Another transformation defined in Schema salad is simplification of data type definitions.
+Type `<T>` ending with `?` should be transformed to `[<T>, "null"]`.
+Type `<T>` ending with `[]` should be transformed to `{"type": "array", "items": <T>}`
+
 ## Extensions and Metadata
 
 Input metadata (for example, a lab sample identifier) may be represented within