Update Mods.Common CSProj

Platform was misconfigured causing weird msbuild issues.
add make log for make.cmd

Don't need to sync this.
Initial Modifications to add Mods.Common to Makefile.

add project, references to mods.ra, and updated install-core.

There may be other things to add.
Update OpenRA sln

Add Build configuration for Mods.Common
Revert "add make log for make.cmd"

This reverts commit ef257125faaec0462bd7c3875f5993dba443e21c.