Check-cmake

- Fixed false positive for incorrect use of `SYSTEM` in `target_include_directories()` in some cases

- Added check for `add_library()` with implicit type (`STATIC`, `SHARED`, et cetera)

- Fixed line numbers sometimes being wrong in context snippets
- Added check for incorrectly-placed `SYSTEM` in `target_include_directories()`
- Added check for extraneous space in `ExternalProject_Add()` `CMAKE_ARGS`

- Fixed `nocheck`

- Added pragmas for ignoring checks on a line
- Added check for `cmake_minimum_required()` when `project()` is present
- Fixed minor formatting issues

- First public release 🎉&xFE0F;