UPGRADE: some typo fixes and rewording

git-svn-id: https://svn.fhem.de/fhem/trunk@15488 2b470e98-0d58-463d-a4d8-8e2adae1ed80

fhem/UPGRADE

@@ -1,23 +1,25 @@
-This file describes the changes to made for a FHEM installation when upgrading
+This file describes the changes to made in a FHEM installation when upgrading
 _to_ the named version from an older version. It describes no new features,
 only features not working anymore.  It may or may not work to set "attr global
 featurelevel X.Y" (where X.Y is the old FHEM version, e.g. 5.6) in order to
 enable to old feature.
 
 - 2015-11-15 (5.7)
-  - $value{DEVICE} is not set, use Value("DEVICE") instead
+  - In the evaluated perl expression $value{DEVICE} is not set any more, use
+    Value("DEVICE") instead
   - the lastinclude global attribute (as in attr global lastinclude filename)
     is not evaluated anymore, use the following instead:
       define lastinclude notify global:INITIALIZED include filename
-  - % is replaced with $EVENT, and @ with $NAME.
+  - In the evaluated perl expression % was replaced with the event, and @ with
+    the device name. Instead of % $EVENT must be used, and instead of @ $NAME.
     The double %% and @@ is not replaced with a single % and @ anymore.
 
 - 2017-02-19 (5.8)
   - the FHEMWEB csrfToken attribute is set to a random value on each startup,
-    i.e. which is checked when executing a command started via the FHEMWEB HTTP
-    connection. If using something like:
+    which is checked when executing a command started via the FHEMWEB HTTP
+    connection. Something like:
       wget 'http://fhemhost:8083/fhem?cmd=set%20device%20on'
-    one of the solutions is to set "attr WEB csrfToken mySecret" and
+    wont work anymore. One solutions is to set "attr WEB csrfToken mySecret" and
     rewrite the above call to:
       wget 'http://fhemhost:8083/fhem?cmd=set%20device%20on&fwcsrf=mySecret'
     There are other solutions in the FHEM wiki.