Please review one commit at a time, it will make reading much easier.
Obvious part: I cleaned up classes according to these guidelines (better readability and same or better performance). No semantics have changed, you can take my word and just accept these.
foreach over for loops
LINQ oneliners over elaborate loops
0 over 0d 0f 0.0 literals
easy on curly braces
computable properties over parameterless methods
Important part (last 5 commits): Requires your insight.
Pool now resets after creating an item, reset delegate not required anymore, count threading bugfix
Units methods computed "N"+decimals several times, increasing GC thrashing
AngleHelper.ClampBetween changed semantics
It used to behave like clamp (min/max) but I think modulo semantics were intended, it worked the same if min=0 but differrs eg. min=-180 max=+180.
AngleHelper.Clamp renamed to Modulo
This seems to be common terminology on internet: clamp is min/max, while this method implements modulo semantics. Note that other clamping methods in this project do respect this terminology.
Please review one commit at a time, it will make reading much easier.
Obvious part: I cleaned up classes according to these guidelines (better readability and same or better performance). No semantics have changed, you can take my word and just accept these.
Important part (last 5 commits): Requires your insight.