Remove .idea folder and modify .gitignore

Sharing even parts of the .idea folder in worldwide setting is bound to
generate more problems than solutions. Therefore it should be removed
and consequently ignore in .gitignore.

Also adds some Python specific stuff to the .gitignore file.

.gitignore

@@ -1,25 +1,26 @@
 # Byte-compiled / optimized / DLL files
 __pycache__/
 *.py[cod]
+*$py.class
 
 # Distribution / packaging
 *.egg-info/
 
+# Unit test / coverage reports
+htmlcov/
+.coverage
+.coverage.*
+
+# Environments
+.env
+.venv
+env/
+venv/
+
+# mypy
+.mypy_cache/
+.dmypy.json
+dmypy.json
+
 # User-specific stuff
-.idea/**/workspace.xml
-.idea/**/tasks.xml
-.idea/**/usage.statistics.xml
-.idea/**/dictionaries
-.idea/**/shelf
-
-# Generated files
-.idea/**/contentModel.xml
-
-# Sensitive or high-churn files
-.idea/**/dataSources/
-.idea/**/dataSources.ids
-.idea/**/dataSources.local.xml
-.idea/**/sqlDataSources.xml
-.idea/**/dynamic.xml
-.idea/**/uiDesigner.xml
-.idea/**/dbnavigator.xml
+.idea