When performing a debug build, the "deadlock plugin" will be included
in the build, which uses the thread functionality of the std. However,
during compiling there would be an error about a symbol in thread.hpp
not being found (_beginthreadex). As it turns out, this was due to us
having a header file called Process.h, which would shadow the windows-
specific header file defining the mentioned symbol.
Therefore, in this commit we rename the Process base class to
AbstractProcess and rename the files accordingly, fixing that error.
See also: https://stackoverflow.com/q/27230258
