Add compiler warnings (#346)

* Add compiler warnings

Add include_type annotation to position

Add warning for unused includes

Add warning for unused stateful annotation

Add warning for unused functions

Add warning for shadowed variables

Add division by zero warning

Add warning for negative spends

Add warning for unused variables

Add warning for unused parameters

Change the ets table type to set for unused vars

Add warning for unused type defs

Move unused variables warning to the top level

Temporarily disable unused functions warnings

Add all kinds of warnings to a single ets table

Enable warnings separately through options

Use when_option instead of enabled_warnings

Turn warnings into type errors with warn_error option

Enable warning package warn_all

Re-enable unused functions warnings

Report warnings as type errors in a separate function

Make unused_function a recognized warning

Report warnings as a result of compilation

Fix tests and error for unknown warnings options

Fix dialyzer warnings

Do not show warning for variables called "_"

Move warnings handling into a separate module

Do not show warning for unused public functions in namespaces

Add src file name to unused include warning

Mark public functions in namespaces as used

Add tests for added warnings

Add warning for unused return value

Add test for turning warnings into type errors

* Update CHANGELOG

CHANGELOG.md

@@ -6,6 +6,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 ### Added
+- Compiler warnings for the follwing: shadowing, negative spends, division by zero, unused functions, unused includes, unused stateful annotations, unused variables, unused parameters, unused user-defined type, dead return value.
 ### Changed
 ### Removed