Cleanup code to bring it closer to normal F# practice

I went over FSharpx today to get a feel for the design and did some cosmetic code cleanup along the way.

* Use 'T instead of 'a for type variable names
* Use four-space indentation in a couple of places
* Use LazyList.rev instead of lLrev, also for split and some others
* Fix a problem with CSharpTests.fsproj
* Remove some "incomplete pattern match" warnings
* Remove some redundant "with" tokens