Milestone: sha1collisiondetection

Historically, the idea of Cesium appeared after we were discussing a possibility of porting code from [sha1collisiondetection](https://github.com/cr-marcstevens/sha1collisiondetection/) project to [Fenrir](https://github.com/ForNeVeR/Fenrir), a project to create a Git client in .NET.

So, our next milestone is going to be the compilation of said project using Cesium.

Milestone goals:
- take as much of the code as possible in its pristine state
- make sure the project compiles and works
- run project tests

Milestone non-goals:
- take **all** of the project in its pristine state
- integrate with any external build system (say, Make, CMake, MSBuild)

Tasks (a pretty rough list; will be elaborated on the go):
- [x] #68
- [x] #69
- [x] #70
- [x] #71
- [x] #234
- [x] #72
(not a lot of them, thankfully)
- [x] #335
- [x] #346
- [x] #75
- [x] #98
- [x] #99
- [x] #100
- [x] #101
- [x] #102
- [x] #74
- [x] #103
- [x] #104
- [x] #120
- [x] #172
- [x] #173
- [x] #517
- [ ] #332
- [ ] More of the standard library to implement (TBD)
- [ ] More parser constructs (TBD)