Reenable switches that start with a slash on Mono
Reenable switches that start with a slash on Mono

Until now, switches on Mono only supported the '-' syntax instead of '/'.
This was done for simplicity to be able to determine if the parameter is a path or MSBuild switch.

By using a similar heuristic as introduced in https://github.com/Microsoft/msbuild/pull/67,
we can now use slashes as well. The heuristic checks if the first segment of a string with
slashes is a directory on disk, if yes it's very likely a path. Otherwise it's a switch.

Fixes #48

mono/msbuild,sean-gilliam/msbuild,sean-gilliam/msbuild,chipitsine/msbuild,chipitsine/msbuild,rainersigwald/msbuild,jeffkl/msbuild,sean-gilliam/msbuild,jeffkl/msbuild,chipitsine/msbuild,mono/msbuild,AndyGerlicher/msbuild,cdmihai/msbuild,Microsoft/msbuild,AndyGerlicher/msbuild,rainersigwald/msbuild,jeffkl/msbuild,cdmihai/msbuild,cdmihai/msbuild,rainersigwald/msbuild,Microsoft/msbuild,rainersigwald/msbuild,AndyGerlicher/msbuild,mono/msbuild,Microsoft/msbuild,jeffkl/msbuild,Microsoft/msbuild,AndyGerlicher/msbuild,mono/msbuild,cdmihai/msbuild,chipitsine/msbuild,sean-gilliam/msbuild