Cleanup/moving around config inputs sections for 1.15 changelog

CHANGELOG.md

 ## 1.15.0
 
-### Language features
-* Added support for [configuration-specific imports](https://github.com/munificent/dep-interface-libraries/blob/master/Proposal.md).
-  On the VM and dart2js, they can be enabled with `--conditional-directives`.
-
-  The analyzer requires an additional option in an `options` file:
-  ```yaml
-  analyzer:
-    language:
-      enableConditionalDirectives: true
-  ```
-  Then run the analyzer with `--options=<path-to-options-file>`.
-
 ### Core library changes
 
 * `dart:async`
   * Made `StreamView` class a `const` class.
 
 * `dart:core`
   * Added `Uri.queryParametersAll` to handle multiple query parameters with
     the same name.
 
 * `dart:io`
   * Added `SecurityContext.usePrivateKeyBytes`,
     `SecurityContext.useCertificateChainBytes`,
     `SecurityContext.setTrustedCertificatesBytes`, and
     `SecurityContext.setClientAuthoritiesBytes`.
   * **Breaking** The named `directory` argument of
     `SecurityContext.setTrustedCertificates` has been removed.
   * Added support to `SecurityContext` for PKCS12 certificate and key
     containers.
   * All calls in `SecurityContext` that accept certificate data now accept an
     optional named parameter `password`, similar to
     `SecurityContext.usePrivateKeyBytes`, for use as the password for PKCS12
     data.
 
 ### Service protocol changes
 
 * Fixed a documentation bug where the field `extensionRPCs` in `Isolate`
   was not marked optional.
 
+### Experimental language features
+  * Added support for [configuration-specific imports](https://github.com/munificent/dep-interface-libraries/blob/master/Proposal.md).
+    On the VM and `dart2js`, they can be enabled with `--conditional-directives`.
+
+    The analyzer requires additional configuration:
+    ```yaml
+    analyzer:
+      language:
+        enableConditionalDirectives: true
+    ```
+
+    Read about [configuring the analyzer] for more details.
+
+[configuring the analyzer]: https://github.com/dart-lang/sdk/tree/master/pkg/analyzer#configuring-the-analyzer
+
 ## 1.14.2 - 2016-02-09
 
 * Fixes a bug where pub would download packages from pub.dartlang.org even when
   a different hosted URL was specified.
 
 ## 1.14.1 - 2016-02-04
 
 Patch release, resolves one issue:
 
 * Debugger: Fixes a VM crash when a debugger attempts to set a break point
@@ skipping 756 matching lines @@
     they will keep the Dart process alive until they time out. This fixes the
     handling of persistent connections. Previously, the client would shut down
     immediately after a request.
 
   * **Breaking change:** `HttpServer` no longer compresses all traffic by
     default. The new `autoCompress` property can be set to `true` to re-enable
     compression.
 
 * `dart:isolate`: `Isolate.spawnUri` added the optional `packageRoot` argument,
   which controls how it resolves `package:` URIs.