remove deprecated ukmetoffice datapoint provider, cleanup .gitignore (#3952)

- weather ukmetoffice see #3842 , I got a final reminder today per mail
that datapoint will be retired on Dec. 1st.
- cleanup/simplify `.gitignore`

.gitignore

@@ -9,8 +9,7 @@ lib-cov
 coverage
 .lock-wscript
 build/Release
-/node_modules/**/*
-!/tests/node_modules/**/*
+node_modules
 jspm_modules
 .npm
 .node_repl_history
@@ -56,21 +55,15 @@ Temporary Items
 .Trash-*
 
 # Ignore all modules except the default modules.
-/modules/**
-!/modules/default
-!/modules/default/**
-!/modules/README.md**
+modules
+!modules/default
 
-# Ignore changes to the custom css files but keep the sample and main.
-/css/*
-!/css/custom.css.sample
-!/css/main.css
-!/css/roboto.css
-!/css/font-awesome.css
+# Ignore changes to the custom css files but keep others.
+css/custom.css
 
 # Ignore users config file but keep the sample.
-/config/*
-!/config/config.js.sample
+config
+!config/config.js.sample
 
 # Vim
 ## swap