fixed unhandled Python errors during comparison attempts

fixes #1848

Additionally, fixes a type hint and makes sure that the new default
behaviour is to use the environment variable if given.

- Only include src/runtime, no other .NET subproject
- In particular, tests are not contained anymore in the sdist
- Fix accidentally including obj and bin directories in the sdist

* Add unit tests for (U)IntPtr conversions
* Special-case construction of (U)IntPtr
* Check (U)IntPtr size explicitly

…e now callable from Python

Fixed a leak in `NewReference.Move`

also fixed issues with xml docs in the code

implements #1876

…ng sequence protocol to (#1902)

.NET arrays when the target .NET type is `System.Object`. The conversion is still attempted when the
target type is a `System.Array`

fixes #1900

- Supports loading without explicitly specifying the runtime config now
- Exposes information on the loaded runtime

Config-less CoreCLR and improved runtime load message

…heck (which checks for subtype)