The existing c-charp linter used the --syntax check mode of the mono mcs
compiler only. The new mcsc linter tries to compile the files located in
a directory tree located bejond the specified source directory or the
current one if no source is explicitly specified. The resulting module
target is placed in a temporary file managed by ale.
* Support netcore project linting.
* Support check on the fly.
* Remove debug.
* Rename csc.vim to mcs.vim as it should be.
* Update README.
* Update doc.
* Using `=~#` instead of `=~`.
