Bug #392: Map appropriate debug fields to Integer instead of Long

The initial implementation of lsp4j.debug used Long to map JSON's
integer values as the debug protocol spec did not provide range
information.

See also microsoft/debug-adapter-protocol#90

CHANGELOG.md

@@ -8,20 +8,9 @@
 Fixed issues: https://github.com/eclipse/lsp4j/milestone/15?closed=1
 
 Breaking API changes:
- * In DebugProtocol many fields which used to be defined as `Long` are now `Integer`.
-   This is due to changes in DAP 1.36 that clarified these values should be less
-   than or equal to 2147483647 (2^31 - 1)
-    - `OutputEventArguments`: `variablesReference`
-    - `RunInTerminalResponse`: `processId`, `shellProcessId`
-    - `DataBreakpointInfoArguments`: `variablesReference`
-    - `VariablesArguments`: `variablesReference`
-    - `SetVariableResponse`: `variablesReference`, `namedVariables`, `indexedVariables`
-    - `SetVariableArguments`: `variablesReference`
-    - `EvaluateResponse`: `variablesReference`, `namedVariables`, `indexedVariables`
-    - `SetExpressionResponse`: `variablesReference`, `namedVariables`, `indexedVariables`
-    - `Source`: `sourceReference`
-    - `Scope`: `variablesReference`, `namedVariables`, `indexedVariables`
-    - `Variable`: `variablesReference`, `namedVariables`, `indexedVariables`
+ * In DebugProtocol fields which used to be defined as `Long` are now `Integer`.
+   This is due to changes in DAP 1.36 and clarification sought from
+   https://github.com/microsoft/debug-adapter-protocol/issues/90
 
  * The DebugProtocol's `EvaluateResponse`'s field `memoryReference` was previously incorrectly
    declared as `Long`, it is now correctly declared as `String`