make the plugin compatible with 2019.2

ResourceTypesSaver: fetch resource types from official schema JSONs

Validation fails for AWS SAM templates if file is named cloudformatio…

…n.yaml #138

Ugly support for implicit IAM Function roles

fix test

Rewrite CFN JSON detection logic , mostly in .template.

Now YAML and JSON .template should not conflict.

For YAML CFN to be detected in .template, it should still be marked as YAML or CFN YAML in file types.
Relates to: #129

sync to doc

correct isCloudFormationFile, check psiFile too

support IDEA 2018.1 in plugin.xml

tests for #103