* Add IL output option for deterministic output

Thread a new option through the options to the code writing the IL.
For the moment just use a constant for deterministic timestamp, and use 0 as the timestamp in the MVID

* Basic check to prevent wildcard version + deterministic at the same time

* Hash the code, data and metadata, and use for mvid + timestamp

* Fix fsc & fsci help tests by adding in new command line option for deterministic

* tests for command line, wildcard versions, normal non-deterministic behaviour

* Attempt to get CI to support timeout

* Allow PRECMD to call FSI more than once, and use this for copying files and pausing to prevent race-condition

* PortablePdbBuilder use consistent id 

If compiling deterministically, use deterministic id provider support in 
making a pdb builder. see https://github.com/dotnet/roslyn/blob/master/src/Compilers/Core/Portable/PEWriter/PeWriter.cs#L132

* Portable and Embedded pdb now deterministic

* wip: fix up timestamp in pdb, but mvids still out of sequence

* Fix breaking change from rebasing on master

* Add notes about determinism with non portable pdbs
Make the checks for finding embedded guids more
strict and unique

* Throw error if determinsitc build and non-portable pdb specified