Working directories are now set seperately from the commands so they
can later be swapped out when running linters over projects is
supported, and also better support filename mapping for running linters
on other machines in future.
Implements suggestions and recommendations suggested by the first review
of the "Advance C# linter based on mcs -t:module (#952)" pull request.
- Clarifies and simplifies description of linters and options
- Added links to help file and marked the mcsc linter as to be run only
when file in buffer is saved or loaded.
- Added comments to the mcsc.vim file to clarify code
- removed type checks considered not necessary be reviewer.
- addresses findings by vader
- removed call to getcwd and cd in vim script
- handler expands file names relative to route of source tree into
absolute pathes. Fixes errors not being marked when vim is started
from subdirectory of source tree.
- implements tests for mcs.vim and mcsc.vim linter
