Docs: Remove remaining references to file and native scripts

docs/reference/aggregations/metrics/extendedstats-aggregation.asciidoc

@@ -109,7 +109,7 @@ GET /exams/_search
 // CONSOLE
 // TEST[setup:exams]
 
-This will interpret the `script` parameter as an `inline` script with the `painless` script language and no script parameters. To use a file script use the following syntax:
+This will interpret the `script` parameter as an `inline` script with the `painless` script language and no script parameters. To use a stored script use the following syntax:
 
 [source,js]
 --------------------------------------------------

docs/reference/modules/plugins.asciidoc

@@ -6,7 +6,7 @@
 
 Plugins are a way to enhance the basic elasticsearch functionality in a
 custom manner. They range from adding custom mapping types, custom
-analyzers (in a more built in fashion), native scripts, custom discovery
+analyzers (in a more built in fashion), custom script engines, custom discovery
 and more.
 
 See the {plugins}/index.html[Plugins documentation] for more.

docs/reference/modules/scripting/security.asciidoc

@@ -47,21 +47,6 @@ Bad:
 * Users can write arbitrary scripts, queries, `_search` requests.
 * User actions make documents with structure defined by users.
 
-[float]
-[[modules-scripting-security-do-no-weaken]]
-=== Do not weaken script security settings
-By default Elasticsearch will run inline, stored, and filesystem scripts for
-the builtin languages, namely the scripting language Painless, the template
-language Mustache, and the expression language Expressions. These *ought* to be
-safe to expose to trusted users and to your application servers because they
-have strong security sandboxes. The Elasticsearch committers do not support any
-non-sandboxed scripting languages and using any would be a poor choice because:
-1. This drops a layer of security, leaving only Elasticsearch's builtin
-<<modules-scripting-other-layers, security layers>>.
-2. Non-sandboxed scripts have unchecked access to Elasticsearch's internals and
-can cause all kinds of trouble if misused.
-
-
 [float]
 [[modules-scripting-other-layers]]
 === Other security layers

docs/reference/modules/scripting/using.asciidoc

@@ -178,14 +178,12 @@ DELETE _scripts/calculate-score
 === Script Caching
 
 All scripts are cached by default so that they only need to be recompiled
-when updates occur. File scripts keep a static cache and will always reside
-in memory. Both inline and stored scripts are stored in a cache that can evict
-residing scripts. By default, scripts do not have a time-based expiration, but
+when updates occur. By default, scripts do not have a time-based expiration, but
 you can change this behavior by using the `script.cache.expire` setting.
 You can configure the size of this cache by using the `script.cache.max_size` setting.
 By default, the cache size is `100`.
 
 NOTE: The size of stored scripts is limited to 65,535 bytes. This can be
 changed by setting `script.max_size_in_bytes` setting to increase that soft
-limit, but if scripts are really large then alternatives like
-<<modules-scripting-native,native>> scripts should be considered instead.
+limit, but if scripts are really large then a
+<<modules-scripting-engine,native script engine>> should be considered.