aspnetcompiler
Replace the SupportsLinuxEnvironment module/methods with a Platform class.

 * Access class methods: linux? & format_path
 * Use `include Albacore::Support` to access the Platform class directly (like
   a namespace)
 * Remove linux support mentions from the nuget tasks, as they're not used
 * Add tests for as much as possible :)
csc
aspnetcompiler
Use System/FailPatch so we can assert on the actual system command.
fluentmigrator
ilmerge
msbuild
mspec
mstest
nant
nchurn

Removed the parameter methods, even though I do like them better. The property
setters have too much inertia. I also added the `include` property (I must have
missed it last time).

I changed the `env_path` property to an `env_paths` array combined with a semi-
colon and totally quoted.
ncoverconsole, ncoverreport

Test runner should support #build_command_line. NCover runs the target program's
command line directly. So, it has to support exporting it's full command line
back to the NCover task. I accidentally removed them in a previous refactor. I
didn't realize what they were used for.

You can see that they're all implemented the same way. These and the whole
"wrapped command line" tasks could benefit from further refactoring.

XUnit won't work with NCover. XUnit supports only one test assembly per run.
So, the task itself runs multiple command line programs. That's not a supported
case with NCover.
fluentm
ilmerge
mspec
mstest
nant
nchurn
ndepend