Two small errors in openEHR_am_206.bmm

@thomas.beale I updated to the latest version of specifications-ITS-BMM. I only tested components/AM/Release-2.0.6/openEHR_am_206.bmm and found these two errors:

1. “EXPR_VALUE_REF” is specified twice in the “packages” section of “components/LANG/Release-1.0.0/openehr_lang_beom_100.bmm”:

"EXPR_LEAF", "EXPR_LITERAL", "EXPR_VARIABLE_REF", "EXPR_VALUE_REF", "EXPR_FUNCTION_CALL",
"EXPR_OPERATOR", "EXPR_UNARY_OPERATOR", "EXPR_BINARY_OPERATOR", "EXPR_VALUE_REF", "EXPR_FOR_ALL", "OPERATOR_KIND"

2. Missing include for “Integer” used by “VALIDITY_KIND” in “components/BASE/Release-1.0.0/openehr_base_base_types_100.bmm”:

“VALIDITY_KIND” has a property of type “Integer” which requires an include in this file:

------------------------------------------------------
-- inclusions
------------------------------------------------------
includes = <
    ["1"] = <
        id = <"openehr_base_foundation_types_1.1.0">
    >
>

Hi Borut, thanks for finding this. Could you please create a pull request on that repo for these fixes?

@thomas.beale Pull request is ready but I probably need permissions for the push to the repository?

I also fixed other AM/RM releases.